doc2000.c

linux下的MTD设备驱动源代码,配合jffs2 yaffss2文件系统.

				up(&this->lock);
				return -EIO;
			}

			DoC_Command(this, NAND_CMD_SEQIN, 0);
			DoC_Address(this, ADDR_COLUMN_PAGE, to + len256, 0,
				    CDSN_CTRL_ECC_IO);
		}

		DoC_WriteBuf(this, &buf[len256], len - len256);

		if (eccbuf) {
			WriteDOC(CDSN_CTRL_ECC_IO | CDSN_CTRL_CE, docptr,
				 CDSNControl);

			if (DoC_is_Millennium(this)) {
				WriteDOC(0, docptr, NOP);
				WriteDOC(0, docptr, NOP);
				WriteDOC(0, docptr, NOP);
			} else {
				WriteDOC_(0, docptr, this->ioreg);
				WriteDOC_(0, docptr, this->ioreg);
				WriteDOC_(0, docptr, this->ioreg);
			}

			WriteDOC(CDSN_CTRL_ECC_IO | CDSN_CTRL_FLASH_IO | CDSN_CTRL_CE, docptr,
				 CDSNControl);

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

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

#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
		}

		DoC_Command(this, NAND_CMD_PAGEPROG, 0);

		DoC_Command(this, NAND_CMD_STATUS, CDSN_CTRL_WP);
		/* There's an implicit DoC_WaitReady() in DoC_Command */

		if (DoC_is_Millennium(this)) {
			ReadDOC(docptr, ReadPipeInit);
			status = ReadDOC(docptr, LastDataRead);
		} else {
			dummy = ReadDOC(docptr, CDSNSlowIO);
			DoC_Delay(this, 2);
			status = ReadDOC_(docptr, this->ioreg);
		}

		if (status & 1) {
			printk(KERN_ERR "Error programming flash\n");
			/* Error in programming */
			*retlen = 0;
			up(&this->lock);
			return -EIO;
		}

		/* Let the caller know we completed it */
		*retlen += len;
		
		if (eccbuf) {
			unsigned char x[8];
			size_t dummy;
			int ret;

			/* Write the ECC data to flash */
			for (di=0; di<6; di++)
				x[di] = eccbuf[di];
		
			x[6]=0x55;
			x[7]=0x55;
		
			ret = doc_write_oob_nolock(mtd, to, 8, &dummy, x);
			if (ret) {
				up(&this->lock);
				return ret;
			}
		}

		to += len;
		left -= len;
		buf += len;
	}

	up(&this->lock);
	return 0;
}

static int doc_writev_ecc(struct mtd_info *mtd, const struct iovec *vecs, 
			  unsigned long count, loff_t to, size_t *retlen,
			  u_char *eccbuf, struct nand_oobinfo *oobsel)
{
	static char static_buf[512];
	static DECLARE_MUTEX(writev_buf_sem);

	size_t totretlen = 0;
	size_t thisvecofs = 0;
	int ret= 0;

	down(&writev_buf_sem);

	while(count) {
		size_t thislen, thisretlen;
		unsigned char *buf;

		buf = vecs->iov_base + thisvecofs;
		thislen = vecs->iov_len - thisvecofs;


		if (thislen >= 512) {
			thislen = thislen & ~(512-1);
			thisvecofs += thislen;
		} else {
			/* Not enough to fill a page. Copy into buf */
			memcpy(static_buf, buf, thislen);
			buf = &static_buf[thislen];

			while(count && thislen < 512) {
				vecs++;
				count--;
				thisvecofs = min((512-thislen), vecs->iov_len);
				memcpy(buf, vecs->iov_base, thisvecofs);
				thislen += thisvecofs;
				buf += thisvecofs;
			}
			buf = static_buf;
		}
		if (count && thisvecofs == vecs->iov_len) {
			thisvecofs = 0;
			vecs++;
			count--;
		}
		ret = doc_write_ecc(mtd, to, thislen, &thisretlen, buf, eccbuf, oobsel);

		totretlen += thisretlen;

		if (ret || thisretlen != thislen)
			break;

		to += thislen;
	}		

	up(&writev_buf_sem);
	*retlen = totretlen;
	return ret;
}


static int doc_read_oob(struct mtd_info *mtd, loff_t ofs, size_t len,
			size_t * retlen, u_char * buf)
{
	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
	int len256 = 0, ret;
	unsigned long docptr;
	struct Nand *mychip;

	down(&this->lock);

	docptr = this->virtadr;

	mychip = &this->chips[ofs >> this->chipshift];

	if (this->curfloor != mychip->floor) {
		DoC_SelectFloor(this, mychip->floor);
		DoC_SelectChip(this, mychip->chip);
	} else if (this->curchip != mychip->chip) {
		DoC_SelectChip(this, mychip->chip);
	}
	this->curfloor = mychip->floor;
	this->curchip = mychip->chip;

	/* update address for 2M x 8bit devices. OOB starts on the second */
	/* page to maintain compatibility with doc_read_ecc. */
	if (this->page256) {
		if (!(ofs & 0x8))
			ofs += 0x100;
		else
			ofs -= 0x8;
	}

	DoC_Command(this, NAND_CMD_READOOB, CDSN_CTRL_WP);
	DoC_Address(this, ADDR_COLUMN_PAGE, ofs, CDSN_CTRL_WP, 0);

	/* treat crossing 8-byte OOB data for 2M x 8bit devices */
	/* Note: datasheet says it should automaticaly wrap to the */
	/*       next OOB block, but it didn't work here. mf.      */
	if (this->page256 && ofs + len > (ofs | 0x7) + 1) {
		len256 = (ofs | 0x7) + 1 - ofs;
		DoC_ReadBuf(this, buf, len256);

		DoC_Command(this, NAND_CMD_READOOB, CDSN_CTRL_WP);
		DoC_Address(this, ADDR_COLUMN_PAGE, ofs & (~0x1ff),
			    CDSN_CTRL_WP, 0);
	}

	DoC_ReadBuf(this, &buf[len256], len - len256);

	*retlen = len;
	/* Reading the full OOB data drops us off of the end of the page,
         * causing the flash device to go into busy mode, so we need
         * to wait until ready 11.4.1 and Toshiba TC58256FT docs */
	
	ret = DoC_WaitReady(this);

	up(&this->lock);
	return ret;

}

static int doc_write_oob_nolock(struct mtd_info *mtd, loff_t ofs, size_t len,
				size_t * retlen, const u_char * buf)
{
	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
	int len256 = 0;
	unsigned long docptr = this->virtadr;
	struct Nand *mychip = &this->chips[ofs >> this->chipshift];
	volatile int dummy;
	int status;

	//      printk("doc_write_oob(%lx, %d): %2.2X %2.2X %2.2X %2.2X ... %2.2X %2.2X .. %2.2X %2.2X\n",(long)ofs, len,
	//   buf[0], buf[1], buf[2], buf[3], buf[8], buf[9], buf[14],buf[15]);

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

	/* issue the Read2 command to set the pointer to the Spare Data Area. */
	DoC_Command(this, NAND_CMD_READOOB, CDSN_CTRL_WP);

	/* update address for 2M x 8bit devices. OOB starts on the second */
	/* page to maintain compatibility with doc_read_ecc. */
	if (this->page256) {
		if (!(ofs & 0x8))
			ofs += 0x100;
		else
			ofs -= 0x8;
	}

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

	/* treat crossing 8-byte OOB data for 2M x 8bit devices */
	/* Note: datasheet says it should automaticaly wrap to the */
	/*       next OOB block, but it didn't work here. mf.      */
	if (this->page256 && ofs + len > (ofs | 0x7) + 1) {
		len256 = (ofs | 0x7) + 1 - ofs;
		DoC_WriteBuf(this, buf, len256);

		DoC_Command(this, NAND_CMD_PAGEPROG, 0);
		DoC_Command(this, NAND_CMD_STATUS, 0);
		/* DoC_WaitReady() is implicit in DoC_Command */

		if (DoC_is_Millennium(this)) {
			ReadDOC(docptr, ReadPipeInit);
			status = ReadDOC(docptr, LastDataRead);
		} else {
			dummy = ReadDOC(docptr, CDSNSlowIO);
			DoC_Delay(this, 2);
			status = ReadDOC_(docptr, this->ioreg);
		}

		if (status & 1) {
			printk(KERN_ERR "Error programming oob data\n");
			/* There was an error */
			*retlen = 0;
			return -EIO;
		}
		DoC_Command(this, NAND_CMD_SEQIN, 0);
		DoC_Address(this, ADDR_COLUMN_PAGE, ofs & (~0x1ff), 0, 0);
	}

	DoC_WriteBuf(this, &buf[len256], len - len256);

	DoC_Command(this, NAND_CMD_PAGEPROG, 0);
	DoC_Command(this, NAND_CMD_STATUS, 0);
	/* DoC_WaitReady() is implicit in DoC_Command */

	if (DoC_is_Millennium(this)) {
		ReadDOC(docptr, ReadPipeInit);
		status = ReadDOC(docptr, LastDataRead);
	} else {
		dummy = ReadDOC(docptr, CDSNSlowIO);
		DoC_Delay(this, 2);
		status = ReadDOC_(docptr, this->ioreg);
	}

	if (status & 1) {
		printk(KERN_ERR "Error programming oob data\n");
		/* There was an error */
		*retlen = 0;
		return -EIO;
	}

	*retlen = len;
	return 0;

}
 
static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, size_t len,
 			 size_t * retlen, const u_char * buf)
{
 	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
 	int ret;

 	down(&this->lock);
 	ret = doc_write_oob_nolock(mtd, ofs, len, retlen, buf);

 	up(&this->lock);
 	return ret;
}

static int doc_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
	__u32 ofs = instr->addr;
	__u32 len = instr->len;
	volatile int dummy;
	unsigned long docptr;
	struct Nand *mychip;
	int status;

 	down(&this->lock);

	if (ofs & (mtd->erasesize-1) || len & (mtd->erasesize-1)) {
		up(&this->lock);
		return -EINVAL;
	}

	instr->state = MTD_ERASING;
		
	docptr = this->virtadr;

	/* FIXME: Do this in the background. Use timers or schedule_task() */
	while(len) {
		mychip = &this->chips[ofs >> this->chipshift];

		if (this->curfloor != mychip->floor) {
			DoC_SelectFloor(this, mychip->floor);
			DoC_SelectChip(this, mychip->chip);
		} else if (this->curchip != mychip->chip) {
			DoC_SelectChip(this, mychip->chip);
		}
		this->curfloor = mychip->floor;
		this->curchip = mychip->chip;

		DoC_Command(this, NAND_CMD_ERASE1, 0);
		DoC_Address(this, ADDR_PAGE, ofs, 0, 0);
		DoC_Command(this, NAND_CMD_ERASE2, 0);

		DoC_Command(this, NAND_CMD_STATUS, CDSN_CTRL_WP);

		if (DoC_is_Millennium(this)) {
			ReadDOC(docptr, ReadPipeInit);
			status = ReadDOC(docptr, LastDataRead);
		} else {
			dummy = ReadDOC(docptr, CDSNSlowIO);
			DoC_Delay(this, 2);
			status = ReadDOC_(docptr, this->ioreg);
		}

		if (status & 1) {
			printk(KERN_ERR "Error erasing at 0x%x\n", ofs);
			/* There was an error */
			instr->state = MTD_ERASE_FAILED;
			goto callback;
		}
		ofs += mtd->erasesize;
		len -= mtd->erasesize;
	}
	instr->state = MTD_ERASE_DONE;

 callback:
	if (instr->callback)
		instr->callback(instr);

	up(&this->lock);
	return 0;
}


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

int __init init_doc2000(void)
{
       inter_module_register(im_name, THIS_MODULE, &DoC2k_init);
       return 0;
}

static void __exit cleanup_doc2000(void)
{
	struct mtd_info *mtd;
	struct DiskOnChip *this;

	while ((mtd = doc2klist)) {
		this = (struct DiskOnChip *) mtd->priv;
		doc2klist = this->nextdoc;

		del_mtd_device(mtd);

		iounmap((void *) this->virtadr);
		kfree(this->chips);
		kfree(mtd);
	}
	inter_module_unregister(im_name);
}

module_exit(cleanup_doc2000);
module_init(init_doc2000);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[e-mail]> et al.");
MODULE_DESCRIPTION("MTD driver for DiskOnChip 2000 and Millennium");