nand_base.c

老版本的mtd-snap

		else
			nand_wait_ready(mtd);
			
		if (read == len)
			break;	

		/* For subsequent reads align to page boundary. */
		col = 0;
		/* Increment page address */
		realpage++;

		page = realpage & this->pagemask;
		/* Check, if we cross a chip boundary */
		if (!page) {
			chipnr++;
			this->select_chip(mtd, -1);
			this->select_chip(mtd, chipnr);
		}
		/* Check, if the chip supports auto page increment 
		 * or if we have hit a block boundary. 
		*/ 
		if (!NAND_CANAUTOINCR(this) || !(page & blockcheck))
			sndcmd = 1;				
	}

	/* Deselect and wake up anyone waiting on the device */
	if (flags & NAND_GET_DEVICE)
		nand_release_device(mtd);

	/*
	 * Return success, if no ECC failures, else -EBADMSG
	 * fs driver will take care of that, because
	 * retlen == desired len and result == -EBADMSG
	 */
	*retlen = read;
	return ecc_failed ? -EBADMSG : 0;
}

/**
 * nand_read_oob - [MTD Interface] NAND read out-of-band
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @retlen:	pointer to variable to store the number of read bytes
 * @buf:	the databuffer to put data
 *
 * NAND read out-of-band data from the spare area
 */
static int nand_read_oob (struct mtd_info *mtd, loff_t from, size_t len, size_t * retlen, u_char * buf)
{
	int i, col, page, chipnr;
	struct nand_chip *this = mtd->priv;
	int	blockcheck = (1 << (this->phys_erase_shift - this->page_shift)) - 1;

	DEBUG (MTD_DEBUG_LEVEL3, "nand_read_oob: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);

	/* Shift to get page */
	page = (int)(from >> this->page_shift);
	chipnr = (int)(from >> this->chip_shift);
	
	/* Mask to get column */
	col = from & (mtd->oobsize - 1);

	/* Initialize return length value */
	*retlen = 0;

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size) {
		DEBUG (MTD_DEBUG_LEVEL0, "nand_read_oob: Attempt read beyond end of device\n");
		*retlen = 0;
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device (this, mtd , FL_READING);

	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Send the read command */
	this->cmdfunc (mtd, NAND_CMD_READOOB, col, page & this->pagemask);
	/* 
	 * Read the data, if we read more than one page
	 * oob data, let the device transfer the data !
	 */
	i = 0;
	while (i < len) {
		int thislen = mtd->oobsize - col;
		thislen = min_t(int, thislen, len);
		this->read_buf(mtd, &buf[i], thislen);
		i += thislen;

		/* Read more ? */
		if (i < len) {
			page++;
			col = 0;

			/* Check, if we cross a chip boundary */
			if (!(page & this->pagemask)) {
				chipnr++;
				this->select_chip(mtd, -1);
				this->select_chip(mtd, chipnr);
			}
				
			/* Apply delay or wait for ready/busy pin 
			 * Do this before the AUTOINCR check, so no problems
			 * arise if a chip which does auto increment
			 * is marked as NOAUTOINCR by the board driver.
			 */
			if (!this->dev_ready) 
				udelay (this->chip_delay);
			else
				nand_wait_ready(mtd);

			/* Check, if the chip supports auto page increment 
			 * or if we have hit a block boundary. 
			*/ 
			if (!NAND_CANAUTOINCR(this) || !(page & blockcheck)) {
				/* For subsequent page reads set offset to 0 */
			        this->cmdfunc (mtd, NAND_CMD_READOOB, 0x0, page & this->pagemask);
			}
		}
	}

	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	/* Return happy */
	*retlen = len;
	return 0;
}

/**
 * nand_read_raw - [GENERIC] Read raw data including oob into buffer
 * @mtd:	MTD device structure
 * @buf:	temporary buffer
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @ooblen:	number of oob data bytes to read
 *
 * Read raw data including oob into buffer
 */
int nand_read_raw (struct mtd_info *mtd, uint8_t *buf, loff_t from, size_t len, size_t ooblen)
{
	struct nand_chip *this = mtd->priv;
	int page = (int) (from >> this->page_shift);
	int chip = (int) (from >> this->chip_shift);
	int sndcmd = 1;
	int cnt = 0;
	int pagesize = mtd->oobblock + mtd->oobsize;
	int	blockcheck = (1 << (this->phys_erase_shift - this->page_shift)) - 1;

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size) {
		DEBUG (MTD_DEBUG_LEVEL0, "nand_read_raw: Attempt read beyond end of device\n");
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device (this, mtd , FL_READING);

	this->select_chip (mtd, chip);
	
	/* Add requested oob length */
	len += ooblen;
	
	while (len) {
		if (sndcmd)
			this->cmdfunc (mtd, NAND_CMD_READ0, 0, page & this->pagemask);
		sndcmd = 0;	

		this->read_buf (mtd, &buf[cnt], pagesize);

		len -= pagesize;
		cnt += pagesize;
		page++;
		
		if (!this->dev_ready) 
			udelay (this->chip_delay);
		else
			nand_wait_ready(mtd);
			
		/* Check, if the chip supports auto page increment */ 
		if (!NAND_CANAUTOINCR(this) || !(page & blockcheck))
			sndcmd = 1;
	}

	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);
	return 0;
}


/** 
 * nand_prepare_oobbuf - [GENERIC] Prepare the out of band buffer 
 * @mtd:	MTD device structure
 * @fsbuf:	buffer given by fs driver
 * @oobsel:	out of band selection structre
 * @autoplace:	1 = place given buffer into the oob bytes
 * @numpages:	number of pages to prepare
 *
 * Return:
 * 1. Filesystem buffer available and autoplacement is off,
 *    return filesystem buffer
 * 2. No filesystem buffer or autoplace is off, return internal
 *    buffer
 * 3. Filesystem buffer is given and autoplace selected
 *    put data from fs buffer into internal buffer and
 *    retrun internal buffer
 *
 * Note: The internal buffer is filled with 0xff. This must
 * be done only once, when no autoplacement happens
 * Autoplacement sets the buffer dirty flag, which
 * forces the 0xff fill before using the buffer again.
 *
*/
static u_char * nand_prepare_oobbuf (struct mtd_info *mtd, u_char *fsbuf, struct nand_oobinfo *oobsel,
		int autoplace, int numpages)
{
	struct nand_chip *this = mtd->priv;
	int i, len, ofs;

	/* Zero copy fs supplied buffer */
	if (fsbuf && !autoplace) 
		return fsbuf;

	/* Check, if the buffer must be filled with ff again */
	if (this->oobdirty) {	
		memset (this->oob_buf, 0xff, 
			mtd->oobsize << (this->phys_erase_shift - this->page_shift));
		this->oobdirty = 0;
	}	
	
	/* If we have no autoplacement or no fs buffer use the internal one */
	if (!autoplace || !fsbuf)
		return this->oob_buf;
	
	/* Walk through the pages and place the data */
	this->oobdirty = 1;
	ofs = 0;
	while (numpages--) {
		for (i = 0, len = 0; len < mtd->oobavail; i++) {
			int to = ofs + oobsel->oobfree[i][0];
			int num = oobsel->oobfree[i][1];
			memcpy (&this->oob_buf[to], fsbuf, num);
			len += num;
			fsbuf += num;
		}
		ofs += mtd->oobavail;
	}
	return this->oob_buf;
}

#define NOTALIGNED(x) (x & (mtd->oobblock-1)) != 0

/**
 * nand_write - [MTD Interface] compability function for nand_write_ecc
 * @mtd:	MTD device structure
 * @to:		offset to write to
 * @len:	number of bytes to write
 * @retlen:	pointer to variable to store the number of written bytes
 * @buf:	the data to write
 *
 * This function simply calls nand_write_ecc with oob buffer and oobsel = NULL
 *
*/
static int nand_write (struct mtd_info *mtd, loff_t to, size_t len, size_t * retlen, const u_char * buf)
{
	return (nand_write_ecc (mtd, to, len, retlen, buf, NULL, NULL));
}
			   
/**
 * nand_write_ecc - [MTD Interface] NAND write with ECC
 * @mtd:	MTD device structure
 * @to:		offset to write to
 * @len:	number of bytes to write
 * @retlen:	pointer to variable to store the number of written bytes
 * @buf:	the data to write
 * @eccbuf:	filesystem supplied oob data buffer
 * @oobsel:	oob selection structure
 *
 * NAND write with ECC
 */
static int nand_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 startpage, page, ret = -EIO, oob = 0, written = 0, chipnr;
	int autoplace = 0, numpages, totalpages;
	struct nand_chip *this = mtd->priv;
	u_char *oobbuf, *bufstart;
	int	ppblock = (1 << (this->phys_erase_shift - this->page_shift));

	DEBUG (MTD_DEBUG_LEVEL3, "nand_write_ecc: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);

	/* Initialize retlen, in case of early exit */
	*retlen = 0;

	/* Do not allow write past end of device */
	if ((to + len) > mtd->size) {
		DEBUG (MTD_DEBUG_LEVEL0, "nand_write_ecc: Attempt to write past end of page\n");
		return -EINVAL;
	}

	/* reject writes, which are not page aligned */	
	if (NOTALIGNED (to) || NOTALIGNED(len)) {
		printk (KERN_NOTICE "nand_write_ecc: Attempt to write not page aligned data\n");
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device (this, mtd, FL_WRITING);

	/* Calculate chipnr */
	chipnr = (int)(to >> this->chip_shift);
	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Check, if it is write protected */
	if (nand_check_wp(mtd))
		goto out;

	/* if oobsel is NULL, use chip defaults */
	if (oobsel == NULL) 
		oobsel = &mtd->oobinfo;		
		
	/* Autoplace of oob data ? Use the default placement scheme */
	if (oobsel->useecc == MTD_NANDECC_AUTOPLACE) {
		oobsel = this->autooob;
		autoplace = 1;
	}	
	if (oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
		autoplace = 1;

	/* Setup variables and oob buffer */
	totalpages = len >> this->page_shift;
	page = (int) (to >> this->page_shift);
	/* Invalidate the page cache, if we write to the cached page */
	if (page <= this->pagebuf && this->pagebuf < (page + totalpages))  
		this->pagebuf = -1;
	
	/* Set it relative to chip */
	page &= this->pagemask;
	startpage = page;
	/* Calc number of pages we can write in one go */
	numpages = min (ppblock - (startpage  & (ppblock - 1)), totalpages);
	oobbuf = nand_prepare_oobbuf (mtd, eccbuf, oobsel, autoplace, numpages);
	bufstart = (u_char *)buf;

	/* Loop until all data is written */
	while (written < len) {

		this->data_poi = (u_char*) &buf[written];
		/* Write one page. If this is the last page to write
		 * or the last page in this block, then use the
		 * real pageprogram command, else select cached programming
		 * if supported by the chip.
		 */
		ret = nand_write_page (mtd, this, page, &oobbuf[oob], oobsel, (--numpages > 0));
		if (ret) {
			DEBUG (MTD_DEBUG_LEVEL0, "nand_write_ecc: write_page failed %d\n", ret);
			goto out;
		}	
		/* Next oob page */
		oob += mtd->oobsize;
		/* Update written bytes count */
		written += mtd->oobblock;
		if (written == len) 
			goto cmp;
		
		/* Increment page address */
		page++;

		/* Have we hit a block boundary ? Then we have to verify and
		 * if verify is ok, we have to setup the oob buffer for
		 * the next pages.
		*/
		if (!(page & (ppblock - 1))){
			int ofs;
			this->data_poi = bufstart;
			ret = nand_verify_pages (mtd, this, startpage, 
				page - startpage,
				oobbuf, oobsel, chipnr, (eccbuf != NULL));
			if (ret) {
				DEBUG (MTD_DEBUG_LEVEL0, "nand_write_ecc: verify_pages failed %d\n", ret);
				goto out;
			}	
			*retlen = written;

			ofs = autoplace ? mtd->oobavail : mtd->oobsize;
			if (eccbuf)
				eccbuf += (page - startpage) * ofs;
			totalpages -= page - startpage;
			numpages = min (totalpages, ppblock);
			page &= this->pagemask;
			startpage = page;
			oobbuf = nand_prepare_oobbuf (mtd, eccbuf, oobsel, 
					autoplace, numpages);
			/* Check, if we cross a chip boundary */
			if (!page) {
				chipnr++;
				this->select_chip(mtd, -1);
				this->select_chip(mtd, chipnr);
			}
		}
	}
	/* Verify the remaining pages */
cmp:
	this->data_poi = bufstart;
 	ret = nand_verify_pages (mtd, this, startpage, totalpages,
		oobbuf, oobsel, chipnr, (eccbuf != NULL));
	if (!ret)
		*retlen = written;
	else	
		DEBUG (MTD_DEBUG_LEVEL0, "nand_write_ecc: verify_pages failed %d\n", ret);

out:
	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	return ret;
}


/**
 * nand_write_oob - [MTD Interface] NAND write out-of-band
 * @mtd:	MTD device structure
 * @to:		offset to write to
 * @len:	number of bytes to write
 * @retlen:	pointer to variable to store the number of written bytes
 * @buf:	the data to write
 *
 * NAND write out-of-band
 */
static int nand_write_oob (struct mtd_info *mtd, loff_t to, size_t len, size_t * retlen, const u_char * buf)
{
	int column, page, status, ret = -EIO, chipnr;
	struct nand_chip *this = mtd->priv;

	DEBUG (MTD_DEBUG_LEVEL3, "nand_write_oob: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);