onenand_base.c

基于linux-2.6.28的mtd驱动

			break;
		}

		if (mode == MTD_OOB_AUTO)
			onenand_transfer_auto_oob(mtd, buf, column, thislen);
		else
			this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);

		read += thislen;

		if (read == len)
			break;

		buf += thislen;

		/* Read more? */
		if (read < len) {
			/* Page size */
			from += mtd->writesize;
			column = 0;
		}
	}

	ops->oobretlen = read;

	if (ret)
		return ret;

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

	return 0;
}

/**
 * onenand_read - [MTD Interface] Read data from flash
 * @param mtd		MTD device structure
 * @param from		offset to read from
 * @param len		number of bytes to read
 * @param retlen	pointer to variable to store the number of read bytes
 * @param buf		the databuffer to put data
 *
 * Read with ecc
*/
static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
	size_t *retlen, u_char *buf)
{
	struct mtd_oob_ops ops = {
		.len	= len,
		.ooblen	= 0,
		.datbuf	= buf,
		.oobbuf	= NULL,
	};
	int ret;

	onenand_get_device(mtd, FL_READING);
	ret = onenand_read_ops_nolock(mtd, from, &ops);
	onenand_release_device(mtd);

	*retlen = ops.retlen;
	return ret;
}

/**
 * onenand_read_oob - [MTD Interface] Read main and/or out-of-band
 * @param mtd:		MTD device structure
 * @param from:		offset to read from
 * @param ops:		oob operation description structure

 * Read main and/or out-of-band
 */
static int onenand_read_oob(struct mtd_info *mtd, loff_t from,
			    struct mtd_oob_ops *ops)
{
	int ret;

	switch (ops->mode) {
	case MTD_OOB_PLACE:
	case MTD_OOB_AUTO:
		break;
	case MTD_OOB_RAW:
		/* Not implemented yet */
	default:
		return -EINVAL;
	}

	onenand_get_device(mtd, FL_READING);
	if (ops->datbuf)
		ret = onenand_read_ops_nolock(mtd, from, ops);
	else
		ret = onenand_read_oob_nolock(mtd, from, ops);
	onenand_release_device(mtd);

	return ret;
}

/**
 * onenand_bbt_wait - [DEFAULT] wait until the command is done
 * @param mtd		MTD device structure
 * @param state		state to select the max. timeout value
 *
 * Wait for command done.
 */
static int onenand_bbt_wait(struct mtd_info *mtd, int state)
{
	struct onenand_chip *this = mtd->priv;
	unsigned long timeout;
	unsigned int interrupt;
	unsigned int ctrl;

	/* The 20 msec is enough */
	timeout = jiffies + msecs_to_jiffies(20);
	while (time_before(jiffies, timeout)) {
		interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
		if (interrupt & ONENAND_INT_MASTER)
			break;
	}
	/* To get correct interrupt status in timeout case */
	interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
	ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);

	if (interrupt & ONENAND_INT_READ) {
		int ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
		if (ecc & ONENAND_ECC_2BIT_ALL) {
			printk(KERN_INFO "onenand_bbt_wait: ecc error = 0x%04x"
				", controller error 0x%04x\n", ecc, ctrl);
			return ONENAND_BBT_READ_ERROR;
		}
	} else {
		printk(KERN_ERR "onenand_bbt_wait: read timeout!"
			"ctrl=0x%04x intr=0x%04x\n", ctrl, interrupt);
		return ONENAND_BBT_READ_FATAL_ERROR;
	}

	/* Initial bad block case: 0x2400 or 0x0400 */
	if (ctrl & ONENAND_CTRL_ERROR) {
		printk(KERN_DEBUG "onenand_bbt_wait: "
			"controller error = 0x%04x\n", ctrl);
		return ONENAND_BBT_READ_ERROR;
	}

	return 0;
}

/**
 * onenand_bbt_read_oob - [MTD Interface] OneNAND read out-of-band for bbt scan
 * @param mtd		MTD device structure
 * @param from		offset to read from
 * @param ops		oob operation description structure
 *
 * OneNAND read out-of-band data from the spare area for bbt scan
 */
int onenand_bbt_read_oob(struct mtd_info *mtd, loff_t from, 
			    struct mtd_oob_ops *ops)
{
	struct onenand_chip *this = mtd->priv;
	int read = 0, thislen, column;
	int ret = 0;
	size_t len = ops->ooblen;
	u_char *buf = ops->oobbuf;

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

	/* Initialize return value */
	ops->oobretlen = 0;

	/* Do not allow reads past end of device */
	if (unlikely((from + len) > mtd->size)) {
		printk(KERN_ERR "onenand_bbt_read_oob: Attempt read beyond end of device\n");
		return ONENAND_BBT_READ_FATAL_ERROR;
	}

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

	column = from & (mtd->oobsize - 1);

	while (read < len) {
		cond_resched();

		thislen = mtd->oobsize - column;
		thislen = min_t(int, thislen, len);

		this->command(mtd, ONENAND_CMD_READOOB, from, mtd->oobsize);

		onenand_update_bufferram(mtd, from, 0);

		ret = onenand_bbt_wait(mtd, FL_READING);
		if (ret)
			break;

		this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);
		read += thislen;
		if (read == len)
			break;

		buf += thislen;

		/* Read more? */
		if (read < len) {
			/* Update Page size */
			from += this->writesize;
			column = 0;
		}
	}

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

	ops->oobretlen = read;
	return ret;
}

#ifdef CONFIG_MTD_ONENAND_VERIFY_WRITE
/**
 * onenand_verify_oob - [GENERIC] verify the oob contents after a write
 * @param mtd		MTD device structure
 * @param buf		the databuffer to verify
 * @param to		offset to read from
 */
static int onenand_verify_oob(struct mtd_info *mtd, const u_char *buf, loff_t to)
{
	struct onenand_chip *this = mtd->priv;
	u_char *oob_buf = this->oob_buf;
	int status, i;

	this->command(mtd, ONENAND_CMD_READOOB, to, mtd->oobsize);
	onenand_update_bufferram(mtd, to, 0);
	status = this->wait(mtd, FL_READING);
	if (status)
		return status;

	this->read_bufferram(mtd, ONENAND_SPARERAM, oob_buf, 0, mtd->oobsize);
	for (i = 0; i < mtd->oobsize; i++)
		if (buf[i] != 0xFF && buf[i] != oob_buf[i])
			return -EBADMSG;

	return 0;
}

/**
 * onenand_verify - [GENERIC] verify the chip contents after a write
 * @param mtd          MTD device structure
 * @param buf          the databuffer to verify
 * @param addr         offset to read from
 * @param len          number of bytes to read and compare
 */
static int onenand_verify(struct mtd_info *mtd, const u_char *buf, loff_t addr, size_t len)
{
	struct onenand_chip *this = mtd->priv;
	void __iomem *dataram;
	int ret = 0;
	int thislen, column;

	while (len != 0) {
		thislen = min_t(int, this->writesize, len);
		column = addr & (this->writesize - 1);
		if (column + thislen > this->writesize)
			thislen = this->writesize - column;

		this->command(mtd, ONENAND_CMD_READ, addr, this->writesize);

		onenand_update_bufferram(mtd, addr, 0);

		ret = this->wait(mtd, FL_READING);
		if (ret)
			return ret;

		onenand_update_bufferram(mtd, addr, 1);

		dataram = this->base + ONENAND_DATARAM;
		dataram += onenand_bufferram_offset(mtd, ONENAND_DATARAM);

		if (memcmp(buf, dataram + column, thislen))
			return -EBADMSG;

		len -= thislen;
		buf += thislen;
		addr += thislen;
	}

	return 0;
}
#else
#define onenand_verify(...)		(0)
#define onenand_verify_oob(...)		(0)
#endif

#define NOTALIGNED(x)	((x & (this->subpagesize - 1)) != 0)

static void onenand_panic_wait(struct mtd_info *mtd)
{
	struct onenand_chip *this = mtd->priv;
	unsigned int interrupt;
	int i;
	
	for (i = 0; i < 2000; i++) {
		interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
		if (interrupt & ONENAND_INT_MASTER)
			break;
		udelay(10);
	}
}

/**
 * onenand_panic_write - [MTD Interface] write buffer to FLASH in a panic context
 * @param mtd		MTD device structure
 * @param to		offset to write to
 * @param len		number of bytes to write
 * @param retlen	pointer to variable to store the number of written bytes
 * @param buf		the data to write
 *
 * Write with ECC
 */
static int onenand_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
			 size_t *retlen, const u_char *buf)
{
	struct onenand_chip *this = mtd->priv;
	int column, subpage;
	int written = 0;
	int ret = 0;

	if (this->state == FL_PM_SUSPENDED)
		return -EBUSY;

	/* Wait for any existing operation to clear */
	onenand_panic_wait(mtd);

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

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

	/* Do not allow writes past end of device */
	if (unlikely((to + len) > mtd->size)) {
		printk(KERN_ERR "onenand_panic_write: Attempt write to past end of device\n");
		return -EINVAL;
	}

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

	column = to & (mtd->writesize - 1);

	/* Loop until all data write */
	while (written < len) {
		int thislen = min_t(int, mtd->writesize - column, len - written);
		u_char *wbuf = (u_char *) buf;

		this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);

		/* Partial page write */
		subpage = thislen < mtd->writesize;
		if (subpage) {
			memset(this->page_buf, 0xff, mtd->writesize);
			memcpy(this->page_buf + column, buf, thislen);
			wbuf = this->page_buf;
		}

		this->write_bufferram(mtd, ONENAND_DATARAM, wbuf, 0, mtd->writesize);
		this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);

		this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);

		onenand_panic_wait(mtd);

		/* In partial page write we don't update bufferram */
		onenand_update_bufferram(mtd, to, !ret && !subpage);
		if (ONENAND_IS_2PLANE(this)) {
			ONENAND_SET_BUFFERRAM1(this);
			onenand_update_bufferram(mtd, to + this->writesize, !ret && !subpage);
		}

		if (ret) {
			printk(KERN_ERR "onenand_panic_write: write failed %d\n", ret);
			break;
		}

		written += thislen;

		if (written == len)
			break;

		column = 0;
		to += thislen;
		buf += thislen;
	}

	*retlen = written;
	return ret;
}

/**
 * onenand_fill_auto_oob - [Internal] oob auto-placement transfer
 * @param mtd		MTD device structure
 * @param oob_buf	oob buffer
 * @param buf		source address
 * @param column	oob offset to write to
 * @param thislen	oob length to write
 */
static int onenand_fill_auto_oob(struct mtd_info *mtd, u_char *oob_buf,
				  const u_char *buf, int column, int thislen)
{
	struct onenand_chip *this = mtd->priv;
	struct nand_oobfree *free;
	int writecol = column;
	int writeend = column + thislen;
	int lastgap = 0;
	unsigned int i;

	free = this->ecclayout->oobfree;
	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES && free->length; i++, free++) {
		if (writecol >= lastgap)
			writecol += free->offset - lastgap;
		if (writeend >= lastgap)
			writeend += free->offset - lastgap;
		lastgap = free->offset + free->length;
	}
	free = this->ecclayout->oobfree;
	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES && free->length; i++, free++) {
		int free_end = free->offset + free->length;
		if (free->offset < writeend && free_end > writecol) {
			int st = max_t(int,free->offset,writecol);
			int ed = min_t(int,free_end,writeend);
			int n = ed - st;
			memcpy(oob_buf + st, buf, n);
			buf += n;
		} else if (column == 0)
			break;
	}
	return 0;
}

/**
 * onenand_write_ops_nolock - [OneNAND Interface] write main and/or out-of-band
 * @param mtd		MTD device structure
 * @param to		offset to write to
 * @param ops		oob operation description structure
 *
 * Write main and/or oob with ECC
 */
static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
				struct mtd_oob_ops *ops)
{
	struct onenand_chip *this = mtd->priv;
	int written = 0, column, thislen, subpage;
	int oobwritten = 0, oobcolumn, thisooblen, oobsize;
	size_t len = ops->len;
	size_t ooblen = ops->ooblen;
	const u_char *buf = ops->datbuf;
	const u_char *oob = ops->oobbuf;
	u_char *oobbuf;
	int ret = 0;

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

	/* Initialize retlen, in case of early exit */
	ops->retlen = 0;
	ops->oobretlen = 0;

	/* Do not allow writes past end of device */
	if (unlikely((to + len) > mtd->size)) {
		printk(KERN_ERR "onenand_write_ops_nolock: Attempt write to past end of device\n");
		return -EINVAL;
	}

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

	if (ops->mode == MTD_OOB_AUTO)
		oobsize = this->ecclayout->oobavail;
	else
		oobsize = mtd->oobsize;

	oobcolumn = to & (mtd->oobsize - 1);

	column = to & (mtd->writesize - 1);

	/* Loop until all data write */
	while (written < len) {
		u_char *wbuf = (u_char *) buf;

		thislen = min_t(int, mtd->writesize - column, len - written);
		thisooblen = min_t(int, oobsize - oobcolumn, ooblen - oobwritten);

		cond_resched();

		this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);

		/* Partial page write */
		subpage = thislen < mtd->writesize;
		if (subpage) {
			memset(this->page_buf, 0xff, mtd->writesize);
			memcpy(this->page_buf + column, buf, thislen);
			wbuf = this->page_buf;
		}