* The NAND device assumes that it is always writing to		 * a cleanly erased page. Hence, it performs its internal		 * write verification only on bits that transitioned from		 * 1 to 0. The device does NOT verify the whole page on		 * a byte by byte basis. It is possible that the page was		 * not completely erased or the page is becoming unusable		 * due to wear. The read with ECC would catch the error		 * later when the ECC page check fails, but we would rather		 * catch it early in the page write stage. Better to write		 * no data than invalid data.		 */		/* Send command to read back the page */		if (col < mtd->eccsize)			nand_command(mtd, NAND_CMD_READ0, col, page);		else			nand_command(mtd, NAND_CMD_READ1, col - 256, page);		this->wait_for_ready();		/* Loop through and verify the data */		for (i = col; i < cnt; i++) {			if (this->data_buf[i] != this->read_data()) {				DEBUG(MTD_DEBUG_LEVEL0,					__FUNCTION__"(): Failed write verify, " \					"page 0x%08x, %6i bytes were succesful\n",					page, *retlen);				i = -EIO;				goto nand_write_exit;			}		}#endif		/* 		 * If we are writing a large amount of data and/or it		 * crosses page or half-page boundaries, we set the		 * the column to zero. It simplifies the program logic.		 */		if (col)			col = 0x00;		/* Update written bytes count */		*retlen += cnt;		/* Increment page address */		page++;			}	/* Return happy */	*retlen = len;	i = 0;nand_write_exit:	/* De-select the NAND device */	nand_deselect();	return i;}/* * NAND write witdh ECC, but only 1 sector! */static intnand_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,               size_t *retlen, const u_char *buf, u_char *ecc_code){	int i, page, cnt, status, ret;	struct nand_chip *this = mtd->priv;	unsigned int sector_size, page_size, oob_size;	DEBUG(MTD_DEBUG_LEVEL3,		__FUNCTION__"(): to = 0x%08x, len = %i\n", (unsigned int)to,		(int)len);	sector_size = this->dev->szS;	page_size = mtd->oobblock;	oob_size = mtd->oobsize;	if (to & (sector_size - 1)) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Not Sector aligned\n");		return -EINVAL;	}	if (len != sector_size) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Only 1 Sector\n");		return -EINVAL;	}	/* Do not allow write past end of page */	if ((to + len) > mtd->size) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Attempted write past end of device\n");		return -EINVAL;	}	/* Shift to get page */	page = ((int) to) >> this->page_shift;	/* Initialize return length value */	*retlen = 0;	/* Select the NAND device */	nand_select();	/* Check the WP bit */	nand_command(mtd, NAND_CMD_STATUS, -1, -1);	this->wait_for_ready();	if (!(this->read_data() & SMC_STAT_NOT_WP)) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Device is write protected!!!\n");		ret = -EPERM;		goto nand_write_err;	}	/* Loop until all data is written */	while (*retlen < len) {		/* Send command to begin auto page programming */		nand_command(mtd, NAND_CMD_SEQIN, 0x00, page);		this->hwcontrol(NAND_CTL_DAT_OUT);		/* Write out complete page of data */		for (i = 0, cnt = 0; i < page_size; i++, cnt++)			this->write_data(buf[(*retlen) + cnt]);		/* Write ones for partial page programming */		for (i = 0; i < oob_size; i++) {#ifdef USE_256BYTE_NAND_FLASH			if (*retlen & (sector_size -1))				this->write_data(ecc_code[SMC_OOB256_SIZE + i]);			else#endif				this->write_data(ecc_code[i]);		}		this->hwcontrol(NAND_CTL_DAT_IN);		/* Send command to actually program the data */		nand_command(mtd, NAND_CMD_PAGEPROG, -1, -1);		this->wait_for_ready();		/*		 * Wait for program operation to complete. This could		 * take up to 3000us (3ms) on some devices, so we try		 * and exit as quickly as possible		 */		status = 0;		for (i = 0; i < 25; i++) {			/* Delay for 125us */			udelay(125);		    			/* Check the status */			nand_command(mtd, NAND_CMD_STATUS, -1, -1);			status = (int)this->read_data();			if (status & SMC_STAT_READY)				break;		}		/* See if device thins it succeeded */		if (status & SMC_STAT_WRITE_ERR) {			DEBUG(MTD_DEBUG_LEVEL0,				__FUNCTION__"(): Failed write, page 0x%08x, " \				"%6i bytes were succesful\n", page, *retlen);			ret = -EIO;			goto nand_write_err;		}#ifdef CONFIG_MTD_NAND_VERIFY_WRITE		/*		 * The NAND device assumes that it is always writing to		 * a cleanly erased page. Hence, it performs its internal		 * write verification only on bits tha transitioned from		 * 1 to 0. The device does NOT verify the whole page on a		 * byte by byte basis. It is possible that the page was		 * not completely erased or the page is becoming unusable		 * due to wear. The read with ECC would catch the error		 * later when the ECC page check fails, but we would rather		 * catch it early in the page write stage. Better to write		 * no data than invalid data.		 */		/* Send command to read back the page */#ifdef USE_256BYTE_NAND_FLASH		if (*retlen & (sector_size - 1))			nand_command(mtd, NAND_CMD_READ0, 0x00, page + 1);		else#endif			nand_command(mtd, NAND_CMD_READ0, 0x00, page);		this->wait_for_ready();		/* Loop through and verify the data */		for (i = 0; i < page_size; i++) {			if (this->data_buf[i] != this->read_data()) {				DEBUG(MTD_DEBUG_LEVEL0,					__FUNCTION__"(): Failed write verify, " \					"page 0x%08x, %6i bytes were succesful\n",					page, *retlen);				ret = -EIO;				goto nand_write_err;			}		}#endif		/* Update written bytes count */		*retlen += cnt;		/* Increment page address */		page++;	}	*retlen = len;	ret = 0;nand_write_err:	/* De-select the NAND device */	nand_deselect();	return ret;}/* * NAND write out-of-band */static intnand_write_oob(struct mtd_info *mtd, loff_t to, size_t len,               size_t *retlen, const u_char *buf){	int i, offset, page, status, ret;	struct nand_chip *this = mtd->priv;	DEBUG(MTD_DEBUG_LEVEL3,		__FUNCTION__"(): to = 0x%08x, len = %i\n", (unsigned int)to,		(int)len);	/* Shift to get page */	page = ((int)to) >> this->page_shift;	/* Mask to get column */	offset = to & 0x1f;	/* Initialize return length value */	*retlen = 0;	/* Do not allow write past end of page */	if ((offset + len) > mtd->oobsize) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Attempt to write past end of page\n");		return -EINVAL;	}	/* Select the NAND device */	nand_select();	/* Check the WP bit */	nand_command(mtd, NAND_CMD_STATUS, -1, -1);	this->wait_for_ready();	if (!(this->read_data() & SMC_STAT_NOT_WP)) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Device is write protected!!!\n");		ret = -EPERM;		goto nand_write_oob_err;	}	/* Write out desired data */	nand_command(mtd, NAND_CMD_SEQIN, offset + mtd->oobblock, page);	this->hwcontrol(NAND_CTL_DAT_OUT);	for (i = 0; i < len; i++)		this->write_data(buf[i]);	this->hwcontrol(NAND_CTL_DAT_IN);	/* Send command to program the OOB data */	nand_command(mtd, NAND_CMD_PAGEPROG, -1, -1);	this->wait_for_ready();	/*	 * Wait for program operation to complete. This could	 * take up to 3000us (3ms) on some devices, so we try	 * and exit as quickly as possible.	 */	status = 0;	for (i = 0; i < 24; i++) {		/* Delay for 125us */		udelay(125);		/* Check the status */		nand_command(mtd, NAND_CMD_STATUS, -1, -1);		this->wait_for_ready();		status = (int)this->read_data();		if (status & SMC_STAT_READY)			break;	}	/* See if device thinks it succeeded */	if (status & SMC_STAT_WRITE_ERR) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Failed write, page 0x%08x\n", page);		ret = -EIO;		goto nand_write_oob_err;	}#ifdef CONFIG_MTD_NAND_VERIFY_WRITE	/* Send command to read back the data */	nand_command(mtd, NAND_CMD_READOOB, offset, page);	this->wait_for_ready();	/* Loop through and verify the data */	for (i = 0; i < len; i++) {		if (buf[i] != this->read_data()) {			DEBUG(MTD_DEBUG_LEVEL0,				__FUNCTION__"(): Failed write verify, page 0x%08x\n",				page);			ret = -EIO;			goto nand_write_oob_err;		}	}#endif	/* Return happy */	*retlen = len;	ret = 0;	nand_write_oob_err:	/* De-select the NAND device */	nand_deselect();	return ret;}/* * NAND erase a block */static intnand_erase(struct mtd_info *mtd, struct erase_info *instr){	int i, page, len, status, pages_per_block;	struct nand_chip *this = mtd->priv;	DEBUG(MTD_DEBUG_LEVEL3,		__FUNCTION__"(): start = 0x%08x, len = %i\n",		(unsigned int)instr->addr, (unsigned int)instr->len);	/* Start address must aligned on block boundary */	if (instr->addr & (mtd->erasesize - 1)) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Unaligned address\n");		return -EINVAL;	}	/* Length must align on block boundary */	if (instr->len & (mtd->erasesize - 1)) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Length not block aligned\n");		return -EINVAL;	}	/* Do not allow erase past end of device */	if ((instr->len + instr->addr) > mtd->size) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Erase past end of device\n");		return -EINVAL;	}	/* Shift to get first page */	page = (int)(instr->addr >> this->page_shift);	/* Calculate pages in each block */	pages_per_block = mtd->erasesize / mtd->oobblock;	/* Select the NAND device */	nand_select();	/* Check the WP bit */	nand_command(mtd, NAND_CMD_STATUS, -1, -1);	this->wait_for_ready();	if (!(this->read_data() & SMC_STAT_NOT_WP)) {		DEBUG(MTD_DEBUG_LEVEL0,			__FUNCTION__"(): Device is write protected!!!\n");		nand_deselect();		return -EIO;	}	/* Loop through the pages */	len = instr->len;	while (len) {		/* Send commands to erase a page */		nand_command(mtd, NAND_CMD_ERASE1, -1, page);		nand_command(mtd, NAND_CMD_ERASE2, -1, -1);		this->wait_for_ready();		/*		 * Wait for program operation to complete. This could		 * take up to 4000us (4ms) on some devices, so we try		 * and exit as quickly as possible.		 */		status = 0;		for (i = 0; i < 32; i++) {			/* Delay for 125us */			udelay(125);			/* Check the status */			nand_command(mtd, NAND_CMD_STATUS, -1, -1);			this->wait_for_ready();			status = (int)this->read_data();			if (status & SMC_STAT_READY)				break;		}		/* See if block erase succeeded */		if (status & SMC_STAT_WRITE_ERR) {			DEBUG(MTD_DEBUG_LEVEL0,				__FUNCTION__"(): Failed erase, page 0x%08x\n", page);			nand_deselect();#if 0			instr->state = MTD_ERASE_FAILED;			if (instr->callback)				instr->callback(instr);#endif			return -EIO;		}		/* Increment page address and decrement length */		len -= mtd->erasesize;		page += pages_per_block;	}	/* De-select the NAND device */	nand_deselect();#if 0	/* Do call back function */	instr->state = MTD_ERASE_DONE;	if (instr->callback)		instr->callback(instr);#endif	/* Return happy */	return 0;	}/* * Scan for the SMC device */intsmc_scan(struct mtd_info *mtd){	int i, nand_maf_id, nand_dev_id;	struct nand_chip *this = mtd->priv;	/* Select the device */	nand_select();	/* Send the command for reading device ID */	nand_command(mtd, NAND_CMD_READID, 0x00, -1);	this->wait_for_ready();	/* Read manufacturer and device IDs */	nand_maf_id = this->read_data();	nand_dev_id = this->read_data();	/* Print and sotre flash device information */	for (i = 0; nand_flash_ids[i].name != NULL; i++) {		if (nand_maf_id == nand_flash_ids[i].manufacture_id &&		    nand_dev_id == nand_flash_ids[i].model_id) {#ifdef USE_256BYTE_NAND_FLASH			if (!mtd->size) {				mtd->name = nand_flash_ids[i].name;				mtd->erasesize = nand_flash_ids[i].erasesize;				mtd->size = (1 << nand_flash_ids[i].chipshift);				mtd->eccsize = 256;				if (nand_flash_ids[i].page256) {					mtd->oobblock = 256;					mtd->oobsize = 8;					this->page_shift = 8;				} else {					mtd->oobblock = 512;					mtd->oobsize = 16;					this->page_shift = 9;				}				this->dev = &nand_smc_info[GET_DI_NUM(nand_flash_ids[i].chipshift)];			}#else			if (!(mtd->size) && !(nand_flash_ids[i].page256)) {				mtd->name = nand_flash_ids[i].name;				mtd->erasesize = nand_flash_ids[i].erasesize;				mtd->size = (1 << nand_flash_ids[i].chipshift);				mtd->eccsize = 256;				mtd->oobblock = 512;				mtd->oobsize = 16;				this->page_shift = 9;				this->dev = &nand_smc_info[GET_DI_NUM(nand_flash_ids[i].chipshift)];			}#endif			printk("NAND device: Manufacture ID:" \				" 0x%02x, Chip ID: 0x%02x (%s)\n",				nand_maf_id, nand_dev_id, mtd->name);			break;		}	    	}	/* De-select the device */	nand_deselect();	/* Print warning message for no device */	if (!mtd->size) {		printk("No NAND device found!!!\n");		return 1;	}	/* Fill in remaining MTD driver data */	mtd->type = MTD_NANDFLASH;	mtd->flags = MTD_CAP_NANDFLASH | MTD_ECC;	mtd->module = NULL;	mtd->ecctype = MTD_ECC_SW;	mtd->erase = nand_erase;	mtd->point = NULL;	mtd->unpoint = NULL;	mtd->read = nand_read;	mtd->write = nand_write;	mtd->read_ecc = nand_read_ecc;	mtd->write_ecc = nand_write_ecc;	mtd->read_oob = nand_read_oob;	mtd->write_oob = nand_write_oob;	mtd->lock = NULL;	mtd->unlock = NULL;	/* Return happy */	return 0;}