onenand_base.c

基于linux-2.6.28的mtd驱动

		unsigned short word;

		/* Align with word(16-bit) size */
		count--;

		/* Read word and save byte */
		word = this->read_word(bufferram + offset + count);
		buffer[count] = (word & 0xff);
	}

	memcpy(buffer, bufferram + offset, count);

	return 0;
}

/**
 * onenand_sync_read_bufferram - [OneNAND Interface] Read the bufferram area with Sync. Burst mode
 * @param mtd		MTD data structure
 * @param area		BufferRAM area
 * @param buffer	the databuffer to put/get data
 * @param offset	offset to read from or write to
 * @param count		number of bytes to read/write
 *
 * Read the BufferRAM area with Sync. Burst Mode
 */
static int onenand_sync_read_bufferram(struct mtd_info *mtd, int area,
		unsigned char *buffer, int offset, size_t count)
{
	struct onenand_chip *this = mtd->priv;
	void __iomem *bufferram;

	bufferram = this->base + area;

	bufferram += onenand_bufferram_offset(mtd, area);

	this->mmcontrol(mtd, ONENAND_SYS_CFG1_SYNC_READ);

	if (ONENAND_CHECK_BYTE_ACCESS(count)) {
		unsigned short word;

		/* Align with word(16-bit) size */
		count--;

		/* Read word and save byte */
		word = this->read_word(bufferram + offset + count);
		buffer[count] = (word & 0xff);
	}

	memcpy(buffer, bufferram + offset, count);

	this->mmcontrol(mtd, 0);

	return 0;
}

/**
 * onenand_write_bufferram - [OneNAND Interface] Write the bufferram area
 * @param mtd		MTD data structure
 * @param area		BufferRAM area
 * @param buffer	the databuffer to put/get data
 * @param offset	offset to read from or write to
 * @param count		number of bytes to read/write
 *
 * Write the BufferRAM area
 */
static int onenand_write_bufferram(struct mtd_info *mtd, int area,
		const unsigned char *buffer, int offset, size_t count)
{
	struct onenand_chip *this = mtd->priv;
	void __iomem *bufferram;

	bufferram = this->base + area;

	bufferram += onenand_bufferram_offset(mtd, area);

	if (ONENAND_CHECK_BYTE_ACCESS(count)) {
		unsigned short word;
		int byte_offset;

		/* Align with word(16-bit) size */
		count--;

		/* Calculate byte access offset */
		byte_offset = offset + count;

		/* Read word and save byte */
		word = this->read_word(bufferram + byte_offset);
		word = (word & ~0xff) | buffer[count];
		this->write_word(word, bufferram + byte_offset);
	}

	memcpy(bufferram + offset, buffer, count);

	return 0;
}

/**
 * onenand_get_2x_blockpage - [GENERIC] Get blockpage at 2x program mode
 * @param mtd		MTD data structure
 * @param addr		address to check
 * @return		blockpage address
 *
 * Get blockpage address at 2x program mode
 */
static int onenand_get_2x_blockpage(struct mtd_info *mtd, loff_t addr)
{
	struct onenand_chip *this = mtd->priv;
	int blockpage, block, page;

	/* Calculate the even block number */
	block = (int) (addr >> this->erase_shift) & ~1;
	/* Is it the odd plane? */
	if (addr & this->writesize)
		block++;
	page = (int) (addr >> (this->page_shift + 1)) & this->page_mask;
	blockpage = (block << 7) | page;

	return blockpage;
}

/**
 * onenand_check_bufferram - [GENERIC] Check BufferRAM information
 * @param mtd		MTD data structure
 * @param addr		address to check
 * @return		1 if there are valid data, otherwise 0
 *
 * Check bufferram if there is data we required
 */
static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)
{
	struct onenand_chip *this = mtd->priv;
	int blockpage, found = 0;
	unsigned int i;

	if (ONENAND_IS_2PLANE(this))
		blockpage = onenand_get_2x_blockpage(mtd, addr);
	else
		blockpage = (int) (addr >> this->page_shift);

	/* Is there valid data? */
	i = ONENAND_CURRENT_BUFFERRAM(this);
	if (this->bufferram[i].blockpage == blockpage)
		found = 1;
	else {
		/* Check another BufferRAM */
		i = ONENAND_NEXT_BUFFERRAM(this);
		if (this->bufferram[i].blockpage == blockpage) {
			ONENAND_SET_NEXT_BUFFERRAM(this);
			found = 1;
		}
	}

	if (found && ONENAND_IS_DDP(this)) {
		/* Select DataRAM for DDP */
		int block = (int) (addr >> this->erase_shift);
		int value = onenand_bufferram_address(this, block);
		this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
	}

	return found;
}

/**
 * onenand_update_bufferram - [GENERIC] Update BufferRAM information
 * @param mtd		MTD data structure
 * @param addr		address to update
 * @param valid		valid flag
 *
 * Update BufferRAM information
 */
static void onenand_update_bufferram(struct mtd_info *mtd, loff_t addr,
		int valid)
{
	struct onenand_chip *this = mtd->priv;
	int blockpage;
	unsigned int i;

	if (ONENAND_IS_2PLANE(this))
		blockpage = onenand_get_2x_blockpage(mtd, addr);
	else
		blockpage = (int) (addr >> this->page_shift);

	/* Invalidate another BufferRAM */
	i = ONENAND_NEXT_BUFFERRAM(this);
	if (this->bufferram[i].blockpage == blockpage)
		this->bufferram[i].blockpage = -1;

	/* Update BufferRAM */
	i = ONENAND_CURRENT_BUFFERRAM(this);
	if (valid)
		this->bufferram[i].blockpage = blockpage;
	else
		this->bufferram[i].blockpage = -1;
}

/**
 * onenand_invalidate_bufferram - [GENERIC] Invalidate BufferRAM information
 * @param mtd		MTD data structure
 * @param addr		start address to invalidate
 * @param len		length to invalidate
 *
 * Invalidate BufferRAM information
 */
static void onenand_invalidate_bufferram(struct mtd_info *mtd, loff_t addr,
		unsigned int len)
{
	struct onenand_chip *this = mtd->priv;
	int i;
	loff_t end_addr = addr + len;

	/* Invalidate BufferRAM */
	for (i = 0; i < MAX_BUFFERRAM; i++) {
		loff_t buf_addr = this->bufferram[i].blockpage << this->page_shift;
		if (buf_addr >= addr && buf_addr < end_addr)
			this->bufferram[i].blockpage = -1;
	}
}

/**
 * onenand_get_device - [GENERIC] Get chip for selected access
 * @param mtd		MTD device structure
 * @param new_state	the state which is requested
 *
 * Get the device and lock it for exclusive access
 */
static int onenand_get_device(struct mtd_info *mtd, int new_state)
{
	struct onenand_chip *this = mtd->priv;
	DECLARE_WAITQUEUE(wait, current);

	/*
	 * Grab the lock and see if the device is available
	 */
	while (1) {
		spin_lock(&this->chip_lock);
		if (this->state == FL_READY) {
			this->state = new_state;
			spin_unlock(&this->chip_lock);
			break;
		}
		if (new_state == FL_PM_SUSPENDED) {
			spin_unlock(&this->chip_lock);
			return (this->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
		}
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&this->wq, &wait);
		spin_unlock(&this->chip_lock);
		schedule();
		remove_wait_queue(&this->wq, &wait);
	}

	return 0;
}

/**
 * onenand_release_device - [GENERIC] release chip
 * @param mtd		MTD device structure
 *
 * Deselect, release chip lock and wake up anyone waiting on the device
 */
static void onenand_release_device(struct mtd_info *mtd)
{
	struct onenand_chip *this = mtd->priv;

	/* Release the chip */
	spin_lock(&this->chip_lock);
	this->state = FL_READY;
	wake_up(&this->wq);
	spin_unlock(&this->chip_lock);
}

/**
 * onenand_transfer_auto_oob - [Internal] oob auto-placement transfer
 * @param mtd		MTD device structure
 * @param buf		destination address
 * @param column	oob offset to read from
 * @param thislen	oob length to read
 */
static int onenand_transfer_auto_oob(struct mtd_info *mtd, uint8_t *buf, int column,
				int thislen)
{
	struct onenand_chip *this = mtd->priv;
	struct nand_oobfree *free;
	int readcol = column;
	int readend = column + thislen;
	int lastgap = 0;
	unsigned int i;
	uint8_t *oob_buf = this->oob_buf;

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

/**
 * onenand_read_ops_nolock - [OneNAND Interface] OneNAND read main and/or out-of-band
 * @param mtd		MTD device structure
 * @param from		offset to read from
 * @param ops:		oob operation description structure
 *
 * OneNAND read main and/or out-of-band data
 */
static int onenand_read_ops_nolock(struct mtd_info *mtd, loff_t from,
				struct mtd_oob_ops *ops)
{
	struct onenand_chip *this = mtd->priv;
	struct mtd_ecc_stats stats;
	size_t len = ops->len;
	size_t ooblen = ops->ooblen;
	u_char *buf = ops->datbuf;
	u_char *oobbuf = ops->oobbuf;
	int read = 0, column, thislen;
	int oobread = 0, oobcolumn, thisooblen, oobsize;
	int ret = 0, boundary = 0;
	int writesize = this->writesize;

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

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

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

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size) {
		printk(KERN_ERR "onenand_read_ops_nolock: Attempt read beyond end of device\n");
		ops->retlen = 0;
		ops->oobretlen = 0;
		return -EINVAL;
	}

	stats = mtd->ecc_stats;

 	/* Read-while-load method */

 	/* Do first load to bufferRAM */
 	if (read < len) {
 		if (!onenand_check_bufferram(mtd, from)) {
			this->command(mtd, ONENAND_CMD_READ, from, writesize);
 			ret = this->wait(mtd, FL_READING);
 			onenand_update_bufferram(mtd, from, !ret);
			if (ret == -EBADMSG)
				ret = 0;
 		}
 	}

	thislen = min_t(int, writesize, len - read);
	column = from & (writesize - 1);
	if (column + thislen > writesize)
		thislen = writesize - column;

 	while (!ret) {
 		/* If there is more to load then start next load */
 		from += thislen;
 		if (read + thislen < len) {
			this->command(mtd, ONENAND_CMD_READ, from, writesize);
 			/*
 			 * Chip boundary handling in DDP
 			 * Now we issued chip 1 read and pointed chip 1
 			 * bufferam so we have to point chip 0 bufferam.
 			 */
 			if (ONENAND_IS_DDP(this) &&
 			    unlikely(from == (this->chipsize >> 1))) {
 				this->write_word(ONENAND_DDP_CHIP0, this->base + ONENAND_REG_START_ADDRESS2);
 				boundary = 1;
 			} else
 				boundary = 0;
 			ONENAND_SET_PREV_BUFFERRAM(this);
 		}
 		/* While load is going, read from last bufferRAM */
 		this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, thislen);

		/* Read oob area if needed */
		if (oobbuf) {
			thisooblen = oobsize - oobcolumn;
			thisooblen = min_t(int, thisooblen, ooblen - oobread);

			if (ops->mode == MTD_OOB_AUTO)
				onenand_transfer_auto_oob(mtd, oobbuf, oobcolumn, thisooblen);
			else
				this->read_bufferram(mtd, ONENAND_SPARERAM, oobbuf, oobcolumn, thisooblen);
			oobread += thisooblen;
			oobbuf += thisooblen;
			oobcolumn = 0;
		}

 		/* See if we are done */
 		read += thislen;
 		if (read == len)
 			break;
 		/* Set up for next read from bufferRAM */
 		if (unlikely(boundary))
 			this->write_word(ONENAND_DDP_CHIP1, this->base + ONENAND_REG_START_ADDRESS2);
 		ONENAND_SET_NEXT_BUFFERRAM(this);
 		buf += thislen;
		thislen = min_t(int, writesize, len - read);
 		column = 0;
 		cond_resched();
 		/* Now wait for load */
 		ret = this->wait(mtd, FL_READING);
 		onenand_update_bufferram(mtd, from, !ret);
		if (ret == -EBADMSG)
			ret = 0;
 	}

	/*
	 * Return success, if no ECC failures, else -EBADMSG
	 * fs driver will take care of that, because
	 * retlen == desired len and result == -EBADMSG
	 */
	ops->retlen = read;
	ops->oobretlen = oobread;

	if (ret)
		return ret;

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

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

/**
 * onenand_read_oob_nolock - [MTD Interface] OneNAND read out-of-band
 * @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
 */
static int onenand_read_oob_nolock(struct mtd_info *mtd, loff_t from,
			struct mtd_oob_ops *ops)
{
	struct onenand_chip *this = mtd->priv;
	struct mtd_ecc_stats stats;
	int read = 0, thislen, column, oobsize;
	size_t len = ops->ooblen;
	mtd_oob_mode_t mode = ops->mode;
	u_char *buf = ops->oobbuf;
	int ret = 0;

	from += ops->ooboffs;

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

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

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

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

	if (unlikely(column >= oobsize)) {
		printk(KERN_ERR "onenand_read_oob_nolock: Attempted to start read outside oob\n");
		return -EINVAL;
	}

	/* Do not allow reads past end of device */
	if (unlikely(from >= mtd->size ||
		     column + len > ((mtd->size >> this->page_shift) -
				     (from >> this->page_shift)) * oobsize)) {
		printk(KERN_ERR "onenand_read_oob_nolock: Attempted to read beyond end of device\n");
		return -EINVAL;
	}

	stats = mtd->ecc_stats;

	while (read < len) {
		cond_resched();

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

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

		onenand_update_bufferram(mtd, from, 0);

		ret = this->wait(mtd, FL_READING);
		if (ret && ret != -EBADMSG) {
			printk(KERN_ERR "onenand_read_oob_nolock: read failed = 0x%x\n", ret);