nand_base.c

基于linux-2.6.28的mtd驱动

					roffs -= free->length;
					continue;
				}
				boffs = free->offset + roffs;
				bytes = min_t(size_t, len,
					      (free->length - roffs));
				roffs = 0;
			} else {
				bytes = min_t(size_t, len, free->length);
				boffs = free->offset;
			}
			memcpy(oob, chip->oob_poi + boffs, bytes);
			oob += bytes;
		}
		return oob;
	}
	default:
		BUG();
	}
	return NULL;
}

/**
 * nand_do_read_ops - [Internal] Read data with ECC
 *
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @ops:	oob ops structure
 *
 * Internal function. Called with chip held.
 */
static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
			    struct mtd_oob_ops *ops)
{
	int chipnr, page, realpage, col, bytes, aligned;
	struct nand_chip *chip = mtd->priv;
	struct mtd_ecc_stats stats;
	int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
	int sndcmd = 1;
	int ret = 0;
	uint32_t readlen = ops->len;
	uint32_t oobreadlen = ops->ooblen;
	uint8_t *bufpoi, *oob, *buf;

	stats = mtd->ecc_stats;

	chipnr = (int)(from >> chip->chip_shift);
	chip->select_chip(mtd, chipnr);

	realpage = (int)(from >> chip->page_shift);
	page = realpage & chip->pagemask;

	col = (int)(from & (mtd->writesize - 1));

	buf = ops->datbuf;
	oob = ops->oobbuf;

	while(1) {
		bytes = min(mtd->writesize - col, readlen);
		aligned = (bytes == mtd->writesize);

		/* Is the current page in the buffer ? */
		if (realpage != chip->pagebuf || oob) {
			bufpoi = aligned ? buf : chip->buffers->databuf;

			if (likely(sndcmd)) {
				chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
				sndcmd = 0;
			}

			/* Now read the page into the buffer */
			if (unlikely(ops->mode == MTD_OOB_RAW))
				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi);
			else if (!aligned && NAND_SUBPAGE_READ(chip) && !oob)
				ret = chip->ecc.read_subpage(mtd, chip, col, bytes, bufpoi);
			else
				ret = chip->ecc.read_page(mtd, chip, bufpoi);
			if (ret < 0)
				break;

			/* Transfer not aligned data */
			if (!aligned) {
				if (!NAND_SUBPAGE_READ(chip) && !oob)
					chip->pagebuf = realpage;
				memcpy(buf, chip->buffers->databuf + col, bytes);
			}

			buf += bytes;

			if (unlikely(oob)) {
				/* Raw mode does data:oob:data:oob */
				if (ops->mode != MTD_OOB_RAW) {
					int toread = min(oobreadlen,
						chip->ecc.layout->oobavail);
					if (toread) {
						oob = nand_transfer_oob(chip,
							oob, ops, toread);
						oobreadlen -= toread;
					}
				} else
					buf = nand_transfer_oob(chip,
						buf, ops, mtd->oobsize);
			}

			if (!(chip->options & NAND_NO_READRDY)) {
				/*
				 * 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 (!chip->dev_ready)
					udelay(chip->chip_delay);
				else
					nand_wait_ready(mtd);
			}
		} else {
			memcpy(buf, chip->buffers->databuf + col, bytes);
			buf += bytes;
		}

		readlen -= bytes;

		if (!readlen)
			break;

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

		page = realpage & chip->pagemask;
		/* Check, if we cross a chip boundary */
		if (!page) {
			chipnr++;
			chip->select_chip(mtd, -1);
			chip->select_chip(mtd, chipnr);
		}

		/* Check, if the chip supports auto page increment
		 * or if we have hit a block boundary.
		 */
		if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck))
			sndcmd = 1;
	}

	ops->retlen = ops->len - (size_t) readlen;
	if (oob)
		ops->oobretlen = ops->ooblen - oobreadlen;

	if (ret)
		return ret;

	if (mtd->ecc_stats.failed - stats.failed)
		return -EBADMSG;

	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
}

/**
 * nand_read - [MTD Interface] MTD compability function for nand_do_read_ecc
 * @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
 *
 * Get hold of the chip and call nand_do_read
 */
static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
		     size_t *retlen, uint8_t *buf)
{
	struct nand_chip *chip = mtd->priv;
	int ret;

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size)
		return -EINVAL;
	if (!len)
		return 0;

	nand_get_device(chip, mtd, FL_READING);

	chip->ops.len = len;
	chip->ops.datbuf = buf;
	chip->ops.oobbuf = NULL;

	ret = nand_do_read_ops(mtd, from, &chip->ops);

	*retlen = chip->ops.retlen;

	nand_release_device(mtd);

	return ret;
}

/**
 * nand_read_oob_std - [REPLACABLE] the most common OOB data read function
 * @mtd:	mtd info structure
 * @chip:	nand chip info structure
 * @page:	page number to read
 * @sndcmd:	flag whether to issue read command or not
 */
static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
			     int page, int sndcmd)
{
	if (sndcmd) {
		chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
		sndcmd = 0;
	}
	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
	return sndcmd;
}

/**
 * nand_read_oob_syndrome - [REPLACABLE] OOB data read function for HW ECC
 *			    with syndromes
 * @mtd:	mtd info structure
 * @chip:	nand chip info structure
 * @page:	page number to read
 * @sndcmd:	flag whether to issue read command or not
 */
static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
				  int page, int sndcmd)
{
	uint8_t *buf = chip->oob_poi;
	int length = mtd->oobsize;
	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
	int eccsize = chip->ecc.size;
	uint8_t *bufpoi = buf;
	int i, toread, sndrnd = 0, pos;

	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
	for (i = 0; i < chip->ecc.steps; i++) {
		if (sndrnd) {
			pos = eccsize + i * (eccsize + chunk);
			if (mtd->writesize > 512)
				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
			else
				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
		} else
			sndrnd = 1;
		toread = min_t(int, length, chunk);
		chip->read_buf(mtd, bufpoi, toread);
		bufpoi += toread;
		length -= toread;
	}
	if (length > 0)
		chip->read_buf(mtd, bufpoi, length);

	return 1;
}

/**
 * nand_write_oob_std - [REPLACABLE] the most common OOB data write function
 * @mtd:	mtd info structure
 * @chip:	nand chip info structure
 * @page:	page number to write
 */
static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
			      int page)
{
	int status = 0;
	const uint8_t *buf = chip->oob_poi;
	int length = mtd->oobsize;

	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
	chip->write_buf(mtd, buf, length);
	/* Send command to program the OOB data */
	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);

	status = chip->waitfunc(mtd, chip);

	return status & NAND_STATUS_FAIL ? -EIO : 0;
}

/**
 * nand_write_oob_syndrome - [REPLACABLE] OOB data write function for HW ECC
 *			     with syndrome - only for large page flash !
 * @mtd:	mtd info structure
 * @chip:	nand chip info structure
 * @page:	page number to write
 */
static int nand_write_oob_syndrome(struct mtd_info *mtd,
				   struct nand_chip *chip, int page)
{
	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
	int eccsize = chip->ecc.size, length = mtd->oobsize;
	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
	const uint8_t *bufpoi = chip->oob_poi;

	/*
	 * data-ecc-data-ecc ... ecc-oob
	 * or
	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
	 */
	if (!chip->ecc.prepad && !chip->ecc.postpad) {
		pos = steps * (eccsize + chunk);
		steps = 0;
	} else
		pos = eccsize;

	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
	for (i = 0; i < steps; i++) {
		if (sndcmd) {
			if (mtd->writesize <= 512) {
				uint32_t fill = 0xFFFFFFFF;

				len = eccsize;
				while (len > 0) {
					int num = min_t(int, len, 4);
					chip->write_buf(mtd, (uint8_t *)&fill,
							num);
					len -= num;
				}
			} else {
				pos = eccsize + i * (eccsize + chunk);
				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
			}
		} else
			sndcmd = 1;
		len = min_t(int, length, chunk);
		chip->write_buf(mtd, bufpoi, len);
		bufpoi += len;
		length -= len;
	}
	if (length > 0)
		chip->write_buf(mtd, bufpoi, length);

	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
	status = chip->waitfunc(mtd, chip);

	return status & NAND_STATUS_FAIL ? -EIO : 0;
}

/**
 * nand_do_read_oob - [Intern] NAND read out-of-band
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @ops:	oob operations description structure
 *
 * NAND read out-of-band data from the spare area
 */
static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
			    struct mtd_oob_ops *ops)
{
	int page, realpage, chipnr, sndcmd = 1;
	struct nand_chip *chip = mtd->priv;
	int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
	int readlen = ops->ooblen;
	int len;
	uint8_t *buf = ops->oobbuf;

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

	if (ops->mode == MTD_OOB_AUTO)
		len = chip->ecc.layout->oobavail;
	else
		len = mtd->oobsize;

	if (unlikely(ops->ooboffs >= len)) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
			"Attempt to start read outside oob\n");
		return -EINVAL;
	}

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

	chipnr = (int)(from >> chip->chip_shift);
	chip->select_chip(mtd, chipnr);

	/* Shift to get page */
	realpage = (int)(from >> chip->page_shift);
	page = realpage & chip->pagemask;

	while(1) {
		sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd);

		len = min(len, readlen);
		buf = nand_transfer_oob(chip, buf, ops, len);

		if (!(chip->options & NAND_NO_READRDY)) {
			/*
			 * 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 (!chip->dev_ready)
				udelay(chip->chip_delay);
			else
				nand_wait_ready(mtd);
		}

		readlen -= len;
		if (!readlen)
			break;

		/* Increment page address */
		realpage++;

		page = realpage & chip->pagemask;
		/* Check, if we cross a chip boundary */
		if (!page) {
			chipnr++;
			chip->select_chip(mtd, -1);
			chip->select_chip(mtd, chipnr);
		}

		/* Check, if the chip supports auto page increment
		 * or if we have hit a block boundary.
		 */
		if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck))
			sndcmd = 1;
	}

	ops->oobretlen = ops->ooblen;
	return 0;
}

/**
 * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @ops:	oob operation description structure
 *
 * NAND read data and/or out-of-band data
 */
static int nand_read_oob(struct mtd_info *mtd, loff_t from,
			 struct mtd_oob_ops *ops)
{
	struct nand_chip *chip = mtd->priv;
	int ret = -ENOTSUPP;

	ops->retlen = 0;

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

	nand_get_device(chip, mtd, FL_READING);

	switch(ops->mode) {
	case MTD_OOB_PLACE:
	case MTD_OOB_AUTO:
	case MTD_OOB_RAW:
		break;

	default:
		goto out;
	}

	if (!ops->datbuf)
		ret = nand_do_read_oob(mtd, from, ops);
	else
		ret = nand_do_read_ops(mtd, from, ops);

 out:
	nand_release_device(mtd);
	return ret;
}


/**
 * nand_write_page_raw - [Intern] raw page write function
 * @mtd:	mtd info structure
 * @chip:	nand chip info structure
 * @buf:	data buffer
 */
static void nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
				const uint8_t *buf)
{
	chip->write_buf(mtd, buf, mtd->writesize);
	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
}

/**
 * nand_write_page_swecc - [REPLACABLE] software ecc based page write function
 * @mtd:	mtd info structure
 * @chip:	nand chip info structure
 * @buf:	data buffer
 */
static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
				  const uint8_t *buf)
{
	int i, eccsize = chip->ecc.size;
	int eccbytes = chip->ecc.bytes;
	int eccsteps = chip->ecc.steps;
	uint8_t *ecc_calc = chip->buffers->ecccalc;
	const uint8_t *p = buf;