diskonchip.c

基于linux-2.6.28的mtd驱动

	memset((char *)parts, 0, sizeof(parts));
	/* On NFTL, we have to find the media headers before we can read the
	   BBTs, since they're stored in the media header eraseblocks. */
	numparts = nftl_partscan(mtd, parts);
	if (!numparts)
		return -EIO;
	this->bbt_td->options = NAND_BBT_ABSPAGE | NAND_BBT_8BIT |
				NAND_BBT_SAVECONTENT | NAND_BBT_WRITE |
				NAND_BBT_VERSION;
	this->bbt_td->veroffs = 7;
	this->bbt_td->pages[0] = doc->mh0_page + 1;
	if (doc->mh1_page != -1) {
		this->bbt_md->options = NAND_BBT_ABSPAGE | NAND_BBT_8BIT |
					NAND_BBT_SAVECONTENT | NAND_BBT_WRITE |
					NAND_BBT_VERSION;
		this->bbt_md->veroffs = 7;
		this->bbt_md->pages[0] = doc->mh1_page + 1;
	} else {
		this->bbt_md = NULL;
	}

	/* It's safe to set bd=NULL below because NAND_BBT_CREATE is not set.
	   At least as nand_bbt.c is currently written. */
	if ((ret = nand_scan_bbt(mtd, NULL)))
		return ret;
	add_mtd_device(mtd);
#ifdef CONFIG_MTD_PARTITIONS
	if (!no_autopart)
		add_mtd_partitions(mtd, parts, numparts);
#endif
	return 0;
}

static int __init inftl_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[5];

	if (this->numchips > doc->chips_per_floor) {
		printk(KERN_ERR "Multi-floor INFTL devices not yet supported.\n");
		return -EIO;
	}

	if (DoC_is_MillenniumPlus(doc)) {
		this->bbt_td->options = NAND_BBT_2BIT | NAND_BBT_ABSPAGE;
		if (inftl_bbt_write)
			this->bbt_td->options |= NAND_BBT_WRITE;
		this->bbt_td->pages[0] = 2;
		this->bbt_md = NULL;
	} else {
		this->bbt_td->options = NAND_BBT_LASTBLOCK | NAND_BBT_8BIT | NAND_BBT_VERSION;
		if (inftl_bbt_write)
			this->bbt_td->options |= NAND_BBT_WRITE;
		this->bbt_td->offs = 8;
		this->bbt_td->len = 8;
		this->bbt_td->veroffs = 7;
		this->bbt_td->maxblocks = INFTL_BBT_RESERVED_BLOCKS;
		this->bbt_td->reserved_block_code = 0x01;
		this->bbt_td->pattern = "MSYS_BBT";

		this->bbt_md->options = NAND_BBT_LASTBLOCK | NAND_BBT_8BIT | NAND_BBT_VERSION;
		if (inftl_bbt_write)
			this->bbt_md->options |= NAND_BBT_WRITE;
		this->bbt_md->offs = 8;
		this->bbt_md->len = 8;
		this->bbt_md->veroffs = 7;
		this->bbt_md->maxblocks = INFTL_BBT_RESERVED_BLOCKS;
		this->bbt_md->reserved_block_code = 0x01;
		this->bbt_md->pattern = "TBB_SYSM";
	}

	/* It's safe to set bd=NULL below because NAND_BBT_CREATE is not set.
	   At least as nand_bbt.c is currently written. */
	if ((ret = nand_scan_bbt(mtd, NULL)))
		return ret;
	memset((char *)parts, 0, sizeof(parts));
	numparts = inftl_partscan(mtd, parts);
	/* At least for now, require the INFTL Media Header.  We could probably
	   do without it for non-INFTL use, since all it gives us is
	   autopartitioning, but I want to give it more thought. */
	if (!numparts)
		return -EIO;
	add_mtd_device(mtd);
#ifdef CONFIG_MTD_PARTITIONS
	if (!no_autopart)
		add_mtd_partitions(mtd, parts, numparts);
#endif
	return 0;
}

static inline int __init doc2000_init(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;

	this->read_byte = doc2000_read_byte;
	this->write_buf = doc2000_writebuf;
	this->read_buf = doc2000_readbuf;
	this->verify_buf = doc2000_verifybuf;
	this->scan_bbt = nftl_scan_bbt;

	doc->CDSNControl = CDSN_CTRL_FLASH_IO | CDSN_CTRL_ECC_IO;
	doc2000_count_chips(mtd);
	mtd->name = "DiskOnChip 2000 (NFTL Model)";
	return (4 * doc->chips_per_floor);
}

static inline int __init doc2001_init(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;

	this->read_byte = doc2001_read_byte;
	this->write_buf = doc2001_writebuf;
	this->read_buf = doc2001_readbuf;
	this->verify_buf = doc2001_verifybuf;

	ReadDOC(doc->virtadr, ChipID);
	ReadDOC(doc->virtadr, ChipID);
	ReadDOC(doc->virtadr, ChipID);
	if (ReadDOC(doc->virtadr, ChipID) != DOC_ChipID_DocMil) {
		/* It's not a Millennium; it's one of the newer
		   DiskOnChip 2000 units with a similar ASIC.
		   Treat it like a Millennium, except that it
		   can have multiple chips. */
		doc2000_count_chips(mtd);
		mtd->name = "DiskOnChip 2000 (INFTL Model)";
		this->scan_bbt = inftl_scan_bbt;
		return (4 * doc->chips_per_floor);
	} else {
		/* Bog-standard Millennium */
		doc->chips_per_floor = 1;
		mtd->name = "DiskOnChip Millennium";
		this->scan_bbt = nftl_scan_bbt;
		return 1;
	}
}

static inline int __init doc2001plus_init(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;

	this->read_byte = doc2001plus_read_byte;
	this->write_buf = doc2001plus_writebuf;
	this->read_buf = doc2001plus_readbuf;
	this->verify_buf = doc2001plus_verifybuf;
	this->scan_bbt = inftl_scan_bbt;
	this->cmd_ctrl = NULL;
	this->select_chip = doc2001plus_select_chip;
	this->cmdfunc = doc2001plus_command;
	this->ecc.hwctl = doc2001plus_enable_hwecc;

	doc->chips_per_floor = 1;
	mtd->name = "DiskOnChip Millennium Plus";

	return 1;
}

static int __init doc_probe(unsigned long physadr)
{
	unsigned char ChipID;
	struct mtd_info *mtd;
	struct nand_chip *nand;
	struct doc_priv *doc;
	void __iomem *virtadr;
	unsigned char save_control;
	unsigned char tmp, tmpb, tmpc;
	int reg, len, numchips;
	int ret = 0;

	virtadr = ioremap(physadr, DOC_IOREMAP_LEN);
	if (!virtadr) {
		printk(KERN_ERR "Diskonchip ioremap failed: 0x%x bytes at 0x%lx\n", DOC_IOREMAP_LEN, physadr);
		return -EIO;
	}

	/* It's not possible to cleanly detect the DiskOnChip - the
	 * bootup procedure will put the device into reset mode, and
	 * it's not possible to talk to it without actually writing
	 * to the DOCControl register. So we store the current contents
	 * of the DOCControl register's location, in case we later decide
	 * that it's not a DiskOnChip, and want to put it back how we
	 * found it.
	 */
	save_control = ReadDOC(virtadr, DOCControl);

	/* Reset the DiskOnChip ASIC */
	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, virtadr, DOCControl);
	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, virtadr, DOCControl);

	/* Enable the DiskOnChip ASIC */
	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, virtadr, DOCControl);
	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, virtadr, DOCControl);

	ChipID = ReadDOC(virtadr, ChipID);

	switch (ChipID) {
	case DOC_ChipID_Doc2k:
		reg = DoC_2k_ECCStatus;
		break;
	case DOC_ChipID_DocMil:
		reg = DoC_ECCConf;
		break;
	case DOC_ChipID_DocMilPlus16:
	case DOC_ChipID_DocMilPlus32:
	case 0:
		/* Possible Millennium Plus, need to do more checks */
		/* Possibly release from power down mode */
		for (tmp = 0; (tmp < 4); tmp++)
			ReadDOC(virtadr, Mplus_Power);

		/* Reset the Millennium Plus ASIC */
		tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | DOC_MODE_BDECT;
		WriteDOC(tmp, virtadr, Mplus_DOCControl);
		WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);

		mdelay(1);
		/* Enable the Millennium Plus ASIC */
		tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | DOC_MODE_BDECT;
		WriteDOC(tmp, virtadr, Mplus_DOCControl);
		WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);
		mdelay(1);

		ChipID = ReadDOC(virtadr, ChipID);

		switch (ChipID) {
		case DOC_ChipID_DocMilPlus16:
			reg = DoC_Mplus_Toggle;
			break;
		case DOC_ChipID_DocMilPlus32:
			printk(KERN_ERR "DiskOnChip Millennium Plus 32MB is not supported, ignoring.\n");
		default:
			ret = -ENODEV;
			goto notfound;
		}
		break;

	default:
		ret = -ENODEV;
		goto notfound;
	}
	/* Check the TOGGLE bit in the ECC register */
	tmp = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
	tmpb = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
	tmpc = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
	if ((tmp == tmpb) || (tmp != tmpc)) {
		printk(KERN_WARNING "Possible DiskOnChip at 0x%lx failed TOGGLE test, dropping.\n", physadr);
		ret = -ENODEV;
		goto notfound;
	}

	for (mtd = doclist; mtd; mtd = doc->nextdoc) {
		unsigned char oldval;
		unsigned char newval;
		nand = mtd->priv;
		doc = nand->priv;
		/* Use the alias resolution register to determine if this is
		   in fact the same DOC aliased to a new address.  If writes
		   to one chip's alias resolution register change the value on
		   the other chip, they're the same chip. */
		if (ChipID == DOC_ChipID_DocMilPlus16) {
			oldval = ReadDOC(doc->virtadr, Mplus_AliasResolution);
			newval = ReadDOC(virtadr, Mplus_AliasResolution);
		} else {
			oldval = ReadDOC(doc->virtadr, AliasResolution);
			newval = ReadDOC(virtadr, AliasResolution);
		}
		if (oldval != newval)
			continue;
		if (ChipID == DOC_ChipID_DocMilPlus16) {
			WriteDOC(~newval, virtadr, Mplus_AliasResolution);
			oldval = ReadDOC(doc->virtadr, Mplus_AliasResolution);
			WriteDOC(newval, virtadr, Mplus_AliasResolution);	// restore it
		} else {
			WriteDOC(~newval, virtadr, AliasResolution);
			oldval = ReadDOC(doc->virtadr, AliasResolution);
			WriteDOC(newval, virtadr, AliasResolution);	// restore it
		}
		newval = ~newval;
		if (oldval == newval) {
			printk(KERN_DEBUG "Found alias of DOC at 0x%lx to 0x%lx\n", doc->physadr, physadr);
			goto notfound;
		}
	}

	printk(KERN_NOTICE "DiskOnChip found at 0x%lx\n", physadr);

	len = sizeof(struct mtd_info) +
	    sizeof(struct nand_chip) + sizeof(struct doc_priv) + (2 * sizeof(struct nand_bbt_descr));
	mtd = kzalloc(len, GFP_KERNEL);
	if (!mtd) {
		printk(KERN_ERR "DiskOnChip kmalloc (%d bytes) failed!\n", len);
		ret = -ENOMEM;
		goto fail;
	}

	nand			= (struct nand_chip *) (mtd + 1);
	doc			= (struct doc_priv *) (nand + 1);
	nand->bbt_td		= (struct nand_bbt_descr *) (doc + 1);
	nand->bbt_md		= nand->bbt_td + 1;

	mtd->priv		= nand;
	mtd->owner		= THIS_MODULE;

	nand->priv		= doc;
	nand->select_chip	= doc200x_select_chip;
	nand->cmd_ctrl		= doc200x_hwcontrol;
	nand->dev_ready		= doc200x_dev_ready;
	nand->waitfunc		= doc200x_wait;
	nand->block_bad		= doc200x_block_bad;
	nand->ecc.hwctl		= doc200x_enable_hwecc;
	nand->ecc.calculate	= doc200x_calculate_ecc;
	nand->ecc.correct	= doc200x_correct_data;

	nand->ecc.layout	= &doc200x_oobinfo;
	nand->ecc.mode		= NAND_ECC_HW_SYNDROME;
	nand->ecc.size		= 512;
	nand->ecc.bytes		= 6;
	nand->options		= NAND_USE_FLASH_BBT;

	doc->physadr		= physadr;
	doc->virtadr		= virtadr;
	doc->ChipID		= ChipID;
	doc->curfloor		= -1;
	doc->curchip		= -1;
	doc->mh0_page		= -1;
	doc->mh1_page		= -1;
	doc->nextdoc		= doclist;

	if (ChipID == DOC_ChipID_Doc2k)
		numchips = doc2000_init(mtd);
	else if (ChipID == DOC_ChipID_DocMilPlus16)
		numchips = doc2001plus_init(mtd);
	else
		numchips = doc2001_init(mtd);

	if ((ret = nand_scan(mtd, numchips))) {
		/* DBB note: i believe nand_release is necessary here, as
		   buffers may have been allocated in nand_base.  Check with
		   Thomas. FIX ME! */
		/* nand_release will call del_mtd_device, but we haven't yet
		   added it.  This is handled without incident by
		   del_mtd_device, as far as I can tell. */
		nand_release(mtd);
		kfree(mtd);
		goto fail;
	}

	/* Success! */
	doclist = mtd;
	return 0;

 notfound:
	/* Put back the contents of the DOCControl register, in case it's not
	   actually a DiskOnChip.  */
	WriteDOC(save_control, virtadr, DOCControl);
 fail:
	iounmap(virtadr);
	return ret;
}

static void release_nanddoc(void)
{
	struct mtd_info *mtd, *nextmtd;
	struct nand_chip *nand;
	struct doc_priv *doc;

	for (mtd = doclist; mtd; mtd = nextmtd) {
		nand = mtd->priv;
		doc = nand->priv;

		nextmtd = doc->nextdoc;
		nand_release(mtd);
		iounmap(doc->virtadr);
		kfree(mtd);
	}
}

static int __init init_nanddoc(void)
{
	int i, ret = 0;

	/* We could create the decoder on demand, if memory is a concern.
	 * This way we have it handy, if an error happens
	 *
	 * Symbolsize is 10 (bits)
	 * Primitve polynomial is x^10+x^3+1
	 * first consecutive root is 510
	 * primitve element to generate roots = 1
	 * generator polinomial degree = 4
	 */
	rs_decoder = init_rs(10, 0x409, FCR, 1, NROOTS);
	if (!rs_decoder) {
		printk(KERN_ERR "DiskOnChip: Could not create a RS decoder\n");
		return -ENOMEM;
	}

	if (doc_config_location) {
		printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
		ret = doc_probe(doc_config_location);
		if (ret < 0)
			goto outerr;
	} else {
		for (i = 0; (doc_locations[i] != 0xffffffff); i++) {
			doc_probe(doc_locations[i]);
		}
	}
	/* No banner message any more. Print a message if no DiskOnChip
	   found, so the user knows we at least tried. */
	if (!doclist) {
		printk(KERN_INFO "No valid DiskOnChip devices found\n");
		ret = -ENODEV;
		goto outerr;
	}
	return 0;
 outerr:
	free_rs(rs_decoder);
	return ret;
}

static void __exit cleanup_nanddoc(void)
{
	/* Cleanup the nand/DoC resources */
	release_nanddoc();

	/* Free the reed solomon resources */
	if (rs_decoder) {
		free_rs(rs_decoder);
	}
}

module_init(init_nanddoc);
module_exit(cleanup_nanddoc);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[e-mail]>");
MODULE_DESCRIPTION("M-Systems DiskOnChip 2000, Millennium and Millennium Plus device driver\n");