nand_util.c

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	return ret;
}

/**
 * nand_get_lock_status: - query current lock state from one page of NAND
 *			   flash
 *
 * @param meminfo	nand mtd instance
 * @param offset	page address to query (muss be page aligned!)
 *
 * @return		-1 in case of error
 *			>0 lock status:
 *			  bitfield with the following combinations:
 *			  NAND_LOCK_STATUS_TIGHT: page in tight state
 *			  NAND_LOCK_STATUS_LOCK:  page locked
 *			  NAND_LOCK_STATUS_UNLOCK: page unlocked
 *
 */
int nand_get_lock_status(nand_info_t *meminfo, ulong offset)
{
	int ret = 0;
	int chipnr;
	int page;
	struct nand_chip *this = meminfo->priv;

	/* select the NAND device */
	chipnr = (int)(offset >> this->chip_shift);
	this->select_chip(meminfo, chipnr);


	if ((offset & (meminfo->writesize - 1)) != 0) {
		printf ("nand_get_lock_status: "
			"Start address must be beginning of "
			"nand page!\n");
		ret = -1;
		goto out;
	}

	/* check the Lock Status */
	page = (int)(offset >> this->page_shift);
	this->cmdfunc(meminfo, NAND_CMD_LOCK_STATUS, -1, page & this->pagemask);

	ret = this->read_byte(meminfo) & (NAND_LOCK_STATUS_TIGHT
					  | NAND_LOCK_STATUS_LOCK
					  | NAND_LOCK_STATUS_UNLOCK);

 out:
	/* de-select the NAND device */
	this->select_chip(meminfo, -1);
	return ret;
}

/**
 * nand_unlock: - Unlock area of NAND pages
 *		  only one consecutive area can be unlocked at one time!
 *
 * @param meminfo	nand mtd instance
 * @param start		start byte address
 * @param length	number of bytes to unlock (must be a multiple of
 *			page size nand->writesize)
 *
 * @return		0 on success, -1 in case of error
 */
int nand_unlock(nand_info_t *meminfo, ulong start, ulong length)
{
	int ret = 0;
	int chipnr;
	int status;
	int page;
	struct nand_chip *this = meminfo->priv;
	printf ("nand_unlock: start: %08x, length: %d!\n",
		(int)start, (int)length);

	/* select the NAND device */
	chipnr = (int)(start >> this->chip_shift);
	this->select_chip(meminfo, chipnr);

	/* check the WP bit */
	this->cmdfunc(meminfo, NAND_CMD_STATUS, -1, -1);
	if ((this->read_byte(meminfo) & 0x80) == 0) {
		printf ("nand_unlock: Device is write protected!\n");
		ret = -1;
		goto out;
	}

	if ((start & (meminfo->writesize - 1)) != 0) {
		printf ("nand_unlock: Start address must be beginning of "
			"nand page!\n");
		ret = -1;
		goto out;
	}

	if (length == 0 || (length & (meminfo->writesize - 1)) != 0) {
		printf ("nand_unlock: Length must be a multiple of nand page "
			"size!\n");
		ret = -1;
		goto out;
	}

	/* submit address of first page to unlock */
	page = (int)(start >> this->page_shift);
	this->cmdfunc(meminfo, NAND_CMD_UNLOCK1, -1, page & this->pagemask);

	/* submit ADDRESS of LAST page to unlock */
	page += (int)(length >> this->page_shift) - 1;
	this->cmdfunc(meminfo, NAND_CMD_UNLOCK2, -1, page & this->pagemask);

	/* call wait ready function */
	status = this->waitfunc(meminfo, this, FL_WRITING);
	/* see if device thinks it succeeded */
	if (status & 0x01) {
		/* there was an error */
		ret = -1;
		goto out;
	}

 out:
	/* de-select the NAND device */
	this->select_chip(meminfo, -1);
	return ret;
}
#endif

/**
 * get_len_incl_bad
 *
 * Check if length including bad blocks fits into device.
 *
 * @param nand NAND device
 * @param offset offset in flash
 * @param length image length
 * @return image length including bad blocks
 */
static size_t get_len_incl_bad (nand_info_t *nand, size_t offset,
				const size_t length)
{
	size_t len_incl_bad = 0;
	size_t len_excl_bad = 0;
	size_t block_len;

	while (len_excl_bad < length) {
		block_len = nand->erasesize - (offset & (nand->erasesize - 1));

		if (!nand_block_isbad (nand, offset & ~(nand->erasesize - 1)))
			len_excl_bad += block_len;

		len_incl_bad += block_len;
		offset       += block_len;

		if ((offset + len_incl_bad) >= nand->size)
			break;
	}

	return len_incl_bad;
}

/**
 * nand_write_skip_bad:
 *
 * Write image to NAND flash.
 * Blocks that are marked bad are skipped and the is written to the next
 * block instead as long as the image is short enough to fit even after
 * skipping the bad blocks.
 *
 * @param nand  	NAND device
 * @param offset	offset in flash
 * @param length	buffer length
 * @param buf           buffer to read from
 * @return		0 in case of success
 */
int nand_write_skip_bad(nand_info_t *nand, size_t offset, size_t *length,
			u_char *buffer)
{
	int rval;
	size_t left_to_write = *length;
	size_t len_incl_bad;
	u_char *p_buffer = buffer;

	/* Reject writes, which are not page aligned */
	if ((offset & (nand->writesize - 1)) != 0 ||
	    (*length & (nand->writesize - 1)) != 0) {
		printf ("Attempt to write non page aligned data\n");
		return -EINVAL;
	}

	len_incl_bad = get_len_incl_bad (nand, offset, *length);

	if ((offset + len_incl_bad) >= nand->size) {
		printf ("Attempt to write outside the flash area\n");
		return -EINVAL;
	}

	if (len_incl_bad == *length) {
		rval = nand_write (nand, offset, length, buffer);
		if (rval != 0) {
			printf ("NAND write to offset %x failed %d\n",
				offset, rval);
			return rval;
		}
	}

	while (left_to_write > 0) {
		size_t block_offset = offset & (nand->erasesize - 1);
		size_t write_size;

		if (nand_block_isbad (nand, offset & ~(nand->erasesize - 1))) {
			printf ("Skip bad block 0x%08x\n",
				offset & ~(nand->erasesize - 1));
			offset += nand->erasesize - block_offset;
			continue;
		}

		if (left_to_write < (nand->erasesize - block_offset))
			write_size = left_to_write;
		else
			write_size = nand->erasesize - block_offset;

		rval = nand_write (nand, offset, &write_size, p_buffer);
		if (rval != 0) {
			printf ("NAND write to offset %x failed %d\n",
				offset, rval);
			*length -= left_to_write;
			return rval;
		}

		left_to_write -= write_size;
		offset        += write_size;
		p_buffer      += write_size;
	}

	return 0;
}

/**
 * nand_read_skip_bad:
 *
 * Read image from NAND flash.
 * Blocks that are marked bad are skipped and the next block is readen
 * instead as long as the image is short enough to fit even after skipping the
 * bad blocks.
 *
 * @param nand NAND device
 * @param offset offset in flash
 * @param length buffer length, on return holds remaining bytes to read
 * @param buffer buffer to write to
 * @return 0 in case of success
 */
int nand_read_skip_bad(nand_info_t *nand, size_t offset, size_t *length,
		       u_char *buffer)
{
	int rval;
	size_t left_to_read = *length;
	size_t len_incl_bad;
	u_char *p_buffer = buffer;

	len_incl_bad = get_len_incl_bad (nand, offset, *length);

	if ((offset + len_incl_bad) >= nand->size) {
		printf ("Attempt to read outside the flash area\n");
		return -EINVAL;
	}

	if (len_incl_bad == *length) {
		rval = nand_read (nand, offset, length, buffer);
		if (rval != 0) {
			printf ("NAND read from offset %x failed %d\n",
				offset, rval);
			return rval;
		}
	}

	while (left_to_read > 0) {
		size_t block_offset = offset & (nand->erasesize - 1);
		size_t read_length;

		if (nand_block_isbad (nand, offset & ~(nand->erasesize - 1))) {
			printf ("Skipping bad block 0x%08x\n",
				offset & ~(nand->erasesize - 1));
			offset += nand->erasesize - block_offset;
			continue;
		}

		if (left_to_read < (nand->erasesize - block_offset))
			read_length = left_to_read;
		else
			read_length = nand->erasesize - block_offset;

		rval = nand_read (nand, offset, &read_length, p_buffer);
		if (rval != 0) {
			printf ("NAND read from offset %x failed %d\n",
				offset, rval);
			*length -= left_to_read;
			return rval;
		}

		left_to_read -= read_length;
		offset       += read_length;
		p_buffer     += read_length;
	}

	return 0;
}