doc2001plus.c

老版本的mtd-snap

		}
	}
	/* 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;
}

static const char im_name[] = "DoCMilPlus_init";

/* This routine is made available to other mtd code via
 * inter_module_register.  It must only be accessed through
 * inter_module_get which will bump the use count of this module.  The
 * addresses passed back in mtd are valid as long as the use count of
 * this module is non-zero, i.e. between inter_module_get and
 * inter_module_put.  Keith Owens <[e-mail]> 29 Oct 2000.
 */
static 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->ecctype = MTD_ECC_RS_DiskOnChip;
	mtd->size = 0;

	mtd->erasesize = 0;
	mtd->oobblock = 512;
	mtd->oobsize = 16;
	mtd->owner = THIS_MODULE;
	mtd->erase = doc_erase;
	mtd->point = NULL;
	mtd->unpoint = NULL;
	mtd->read = doc_read;
	mtd->write = doc_write;
	mtd->read_ecc = doc_read_ecc;
	mtd->write_ecc = doc_write_ecc;
	mtd->read_oob = doc_read_oob;
	mtd->write_oob = doc_write_oob;
	mtd->sync = NULL;

	this->totlen = 0;
	this->numchips = 0;
	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;
		add_mtd_device(mtd);
		return;
	}
}

#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)
{
	/* Just a special case of doc_read_ecc */
	return doc_read_ecc(mtd, from, len, retlen, buf, NULL, NULL);
}

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

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

	/* 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);

	if (eccbuf) {
		/* 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);
	} else {
		/* disable the ECC engine */
		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
	}

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

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

	if (eccbuf) {
		/* 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 syndrom 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= %02x:%02x:%02x:%02x:%02x:"
				"%02x\n",
				syndrome[0], syndrome[1], syndrome[2],
				syndrome[3], syndrome[4], syndrome[5]);
			printk("          eccbuf= %02x:%02x:%02x:%02x:%02x:"
				"%02x\n",
				eccbuf[0], eccbuf[1], eccbuf[2],
				eccbuf[3], eccbuf[4], eccbuf[5]);
#endif
				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 , Mplus_ECCConf);
	} else {
		/* Read the data via the internal pipeline through CDSN IO
		   register, see Pipelined Read Operations 11.3 */
		MemReadDOC(docptr, buf, len-2);
		buf[len-2] = ReadDOC(docptr, Mplus_LastDataRead);
		buf[len-1] = ReadDOC(docptr, Mplus_LastDataRead);
	}

	/* 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)
{
	char eccbuf[6];
	return doc_write_ecc(mtd, to, len, retlen, buf, eccbuf, NULL);
}

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

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

	/* 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));