/* * YAFFS: Yet another FFS. A NAND-flash specific file system.  * * Copyright (C) 2002 Aleph One Ltd. *   for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */#include <linux/config.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/version.h>#include <linux/slab.h>#include <linux/init.h>#include <linux/list.h>#include <linux/fs.h>#include <linux/proc_fs.h>#include <linux/pagemap.h>#include <linux/mtd/mtd.h>#include <linux/interrupt.h>#include <linux/string.h>#include <linux/locks.h>#include <asm/uaccess.h>#include <linux/mtd/mtd.h>#include <linux/mtd/partitions.h>#include <linux/mtd/nand.h>#define T(x) printk x#define ALLOCATE(x) kmalloc(x,GFP_KERNEL)#define FREE(x)     kfree(x)#define DEFAULT_SIZE_IN_MB 16#define NAND_SHIFT 9static struct mtd_info nandemul_mtd;typedef struct{	__u8 data[528]; // Data + spare	int count[3];   // The programming count for each area of			// the page (0..255,256..511,512..527	int empty;      // is this empty?} nandemul_Page;typedef struct{	nandemul_Page page[32]; // The pages in the block	__u8 damaged; 		// Is the block damaged?	} nandemul_Block;typedef struct{	nandemul_Block **block;	int nBlocks;} nandemul_Device;nandemul_Device device;int sizeInMB = DEFAULT_SIZE_IN_MB;int nandemul_CalcNBlocks(void){        switch(sizeInMB)        {        	case 8:        	case 16:        	case 32:        	case 64:        	case 128:        	case 256:        	case 512:        		break;        	default:        		sizeInMB = DEFAULT_SIZE_IN_MB;        }	return sizeInMB * 64;}static void nandemul_ReallyEraseBlock(int blockNumber){	int i;		nandemul_Block *theBlock = device.block[blockNumber];		for(i = 0; i < 32; i++)	{		memset(theBlock->page[i].data,0xff,528);		theBlock->page[i].count[0] = 0;		theBlock->page[i].count[1] = 0;		theBlock->page[i].count[2] = 0;		theBlock->page[i].empty = 1;	}}static int nandemul_DoErase(int blockNumber){	if(blockNumber < 0 || nandemul_CalcNBlocks())	{		T(("Attempt to erase non-existant block %d\n",blockNumber));	}	else if(device.block[blockNumber]->damaged)	{		T(("Attempt to erase damaged block %d\n",blockNumber));	}	else	{		nandemul_ReallyEraseBlock(blockNumber);	}	return 1;	}int nandemul_Initialise(void){	int i;	int fail = 0;	int nBlocks = nandemul_CalcNBlocks();	int nAllocated = 0;	device.block = ALLOCATE (sizeof(nandemul_Block *) * nBlocks);	if(!device.block) return 0;	for(i=0; i <nBlocks; i++)	{		device.block[i] = NULL;	}		for(i=0; i <nBlocks && !fail; i++)	{		if((device.block[i] = ALLOCATE(sizeof(nandemul_Block))) == 0)		{			fail = 1;		}		else		{			nandemul_ReallyEraseBlock(i);			device.block[i]->damaged = 0;			nAllocated++;		}	}		if(fail)	{		for(i = 0; i < nAllocated; i++)		{			FREE(device.block[i]);		}		FREE(device.block);		T(("Allocation failed, could only allocate %dMB of %dMB requested.\n",		   nAllocated/64,sizeInMB));		return 0;	}	device.nBlocks = nBlocks;	return 1;}int nandemul_DeInitialise(void){	int i;	for(i = 0; i < device.nBlocks; i++)	{		FREE(device.block[i]);		device.block[i] = NULL;	}		FREE(device.block);	device.block = NULL;	return 1;}int nandemul_GetNumberOfBlocks(__u32 *nBlocks){	*nBlocks = device.nBlocks;		return 1;}int nandemul_Reset(void){	// Do nothing	return 1;}int nandemul_Read(__u8 *buffer, __u32 pageAddress,__u32 pageOffset, __u32 nBytes){	unsigned blockN, pageN;		blockN = pageAddress/32;	pageN =  pageAddress % 32;		// TODO: Do tests for valid blockN, pageN, pageOffset	memcpy(buffer,&device.block[blockN]->page[pageN].data[pageOffset],nBytes);		return 1;		}int nandemul_Program(const __u8 *buffer, __u32 pageAddress,__u32 pageOffset, __u32 nBytes){	unsigned blockN, pageN, pageO;		int p0, p1, p2;	int i;		blockN = pageAddress/32;	pageN =  pageAddress % 32;	p0 = 0;	p1 = 0;	p2 = 0;		// TODO: Do tests for valid blockN, pageN, pageOffset    for(i = 0,pageO = pageOffset; i < nBytes; i++, pageO++)    {    	device.block[blockN]->page[pageN].data[pageO] &= buffer[i];			if(pageO < 256) p0 = 1;		else if(pageO <512) p1 = 1;		else p2 = 1;    }		device.block[blockN]->page[pageN].empty = 0;	device.block[blockN]->page[pageN].count[0] += p0;	device.block[blockN]->page[pageN].count[1] += p1;	device.block[blockN]->page[pageN].count[2] += p2;		if(device.block[blockN]->page[pageN].count[0] > 1)	{		T(("block %d page %d first half programmed %d times\n",		    blockN,pageN,device.block[blockN]->page[pageN].count[0]));	}	if(device.block[blockN]->page[pageN].count[1] > 1)	{		T(("block %d page %d second half programmed %d times\n",		    blockN,pageN,device.block[blockN]->page[pageN].count[1]));	}	if(device.block[blockN]->page[pageN].count[2] > 3)	{		T(("block %d page %d spare programmed %d times\n",		    blockN,pageN,device.block[blockN]->page[pageN].count[2]));	}	return 1;	}int nandemul_CauseBitErrors( __u32 pageAddress, __u32 pageOffset, __u8 xorPattern){	unsigned blockN, pageN;		blockN = pageAddress/32;	pageN =  pageAddress % 32;		// TODO: Do tests for valid blockN, pageN, pageOffset    device.block[blockN]->page[pageN].data[pageOffset] ^= xorPattern;		return 1;	}int nandemul_BlockErase(__u32 pageAddress){	unsigned blockN;		blockN = pageAddress/32;	// TODO: Do tests for valid blockN	// TODO: Test that the block has not failed	return nandemul_DoErase(blockN);	}int nandemul_FailBlock(__u32 pageAddress){	unsigned blockN;		blockN = pageAddress/32;	// TODO: Do tests for valid blockN	// TODO: Test that the block has not failed		nandemul_DoErase(blockN);	return 1;}int nandemul_ReadId(__u8 *vendorId, __u8 *deviceId){	*vendorId = 0xEC;	*deviceId = 0x75;		return 1;}int nandemul_CopyPage(__u32 fromPageAddress, __u32 toPageAddress){	__u8 copyBuffer[528];		// TODO: Check the bitplane issue.	nandemul_Read(copyBuffer, fromPageAddress,0,528);	nandemul_Program(copyBuffer, toPageAddress,0,528);		return 1;}int nandemul_ReadStatus(__u8 *status){		*status = 0;		return 1;}#ifdef CONFIG_MTD_NAND_ECC#include <linux/mtd/nand_ecc.h>#endif/* * NAND low-level MTD interface functions */static int nand_read (struct mtd_info *mtd, loff_t from, size_t len,			size_t *retlen, u_char *buf);static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,				size_t *retlen, u_char *buf, u_char *ecc_code);static int nand_read_oob (struct mtd_info *mtd, loff_t from, size_t len,				size_t *retlen, u_char *buf);static int nand_write (struct mtd_info *mtd, loff_t to, size_t len,			size_t *retlen, const u_char *buf);static int nand_write_ecc (struct mtd_info *mtd, loff_t to, size_t len,				size_t *retlen, const u_char *buf,				u_char *ecc_code);static int nand_write_oob (struct mtd_info *mtd, loff_t to, size_t len,				size_t *retlen, const u_char *buf);static int nand_writev (struct mtd_info *mtd, const struct iovec *vecs,				unsigned long count, loff_t to, size_t *retlen);static int nand_erase (struct mtd_info *mtd, struct erase_info *instr);static void nand_sync (struct mtd_info *mtd);/* * NAND read */static int nand_read (struct mtd_info *mtd, loff_t from, size_t len,			size_t *retlen, u_char *buf){	return nand_read_ecc (mtd, from, len, retlen, buf, NULL);}/* * NAND read with ECC */static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,				size_t *retlen, u_char *buf, u_char *ecc_code){	int 	start, page;	int n = len;	int nToCopy;	/* Do not allow reads past end of device */	if ((from + len) > mtd->size) {		*retlen = 0;		return -EINVAL;	}	/* Initialize return value */	*retlen = 0;	while(n > 0)	{		/* First we calculate the starting page */		page = from >> NAND_SHIFT;		/* Get raw starting column */		start = from & (mtd->oobblock-1);		// OK now check for the curveball where the start and end are in		// the same page		if((start + n) < mtd->oobblock)		{			nToCopy = n;		}		else		{			nToCopy =  mtd->oobblock - start;		}		nandemul_Read(buf, page, start, nToCopy);		n -= nToCopy;		from += nToCopy;		buf += nToCopy;		*retlen += nToCopy;	}	return 0;}/* * NAND read out-of-band */static int nand_read_oob (struct mtd_info *mtd, loff_t from, size_t len,				size_t *retlen, u_char *buf){	int col, page;	DEBUG (MTD_DEBUG_LEVEL3,		"nand_read_oob: from = 0x%08x, len = %i\n", (unsigned int) from,		(int) len);	/* Shift to get page */	page = ((int) from) >> NAND_SHIFT;	/* Mask to get column */	col = from & 0x0f;	/* Initialize return length value */	*retlen = 0;	/* Do not allow reads past end of device */	if ((from + len) > mtd->size) {		DEBUG (MTD_DEBUG_LEVEL0,			"nand_read_oob: Attempt read beyond end of device\n");		*retlen = 0;		return -EINVAL;	}	nandemul_Read(buf,page,512 + col,len);	/* Return happy */	*retlen = len;	return 0;}/* * NAND write */static int nand_write (struct mtd_info *mtd, loff_t to, size_t len,			size_t *retlen, const u_char *buf){	return nand_write_ecc (mtd, to, len, retlen, buf, NULL);}/* * NAND write with ECC */static int nand_write_ecc (struct mtd_info *mtd, loff_t to, size_t len,				size_t *retlen, const u_char *buf,				u_char *ecc_code){	int 	start, page;	int n = len;	int nToCopy;	/* Do not allow reads past end of device */	if ((to + len) > mtd->size) {		*retlen = 0;		return -EINVAL;	}	/* Initialize return value */	*retlen = 0;	while(n > 0)	{		/* First we calculate the starting page */		page = to >> NAND_SHIFT;		/* Get raw starting column */		start = to & (mtd->oobblock - 1);		// OK now check for the curveball where the start and end are in		// the same page		if((start + n) < mtd->oobblock)		{			nToCopy = n;		}		else		{			nToCopy =  mtd->oobblock - start;		}		nandemul_Program(buf, page, start, nToCopy);		n -= nToCopy;		to += nToCopy;		buf += nToCopy;		*retlen += nToCopy;	}	return 0;}/* * NAND write out-of-band */static int nand_write_oob (struct mtd_info *mtd, loff_t to, size_t len,				size_t *retlen, const u_char *buf){	int col, page;	DEBUG (MTD_DEBUG_LEVEL3,		"nand_read_oob: to = 0x%08x, len = %i\n", (unsigned int) to,		(int) len);	/* Shift to get page */	page = ((int) to) >> NAND_SHIFT;	/* Mask to get column */	col = to & 0x0f;	/* Initialize return length value */	*retlen = 0;	/* Do not allow reads past end of device */	if ((to + len) > mtd->size) {		DEBUG (MTD_DEBUG_LEVEL0,			"nand_read_oob: Attempt read beyond end of device\n");		*retlen = 0;		return -EINVAL;	}	nandemul_Program(buf,page,512 + col,len);	/* Return happy */	*retlen = len;	return 0;}/* * NAND write with iovec */static int nand_writev (struct mtd_info *mtd, const struct iovec *vecs,				unsigned long count, loff_t to, size_t *retlen){	return -EINVAL;}/* * NAND erase a block */static int nand_erase (struct mtd_info *mtd, struct erase_info *instr){	int i, nBlocks,block;	DEBUG (MTD_DEBUG_LEVEL3,		"nand_erase: start = 0x%08x, len = %i\n",		(unsigned int) instr->addr, (unsigned int) instr->len);	/* Start address must align on block boundary */	if (instr->addr & (mtd->erasesize - 1)) {		DEBUG (MTD_DEBUG_LEVEL0,			"nand_erase: Unaligned address\n");		return -EINVAL;	}	/* Length must align on block boundary */	if (instr->len & (mtd->erasesize - 1)) {		DEBUG (MTD_DEBUG_LEVEL0,			"nand_erase: 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,			"nand_erase: Erase past end of device\n");		return -EINVAL;	}	nBlocks = instr->len >> (NAND_SHIFT + 5);	block = instr->addr >> (NAND_SHIFT + 5);	for(i = 0; i < nBlocks; i++)	{		nandemul_DoErase(block);		block++;	}	return 0;}/* * NAND sync */static void nand_sync (struct mtd_info *mtd){	DEBUG (MTD_DEBUG_LEVEL3, "nand_sync: called\n");}/* * Scan for the NAND device */int nand_scan (struct mtd_info *mtd,int maxchips){	mtd->oobblock = 512;	mtd->oobsize = 16;	mtd->erasesize = 512 * 32;	mtd->size = sizeInMB * 1024*1024;	/* Fill in remaining MTD driver data */	mtd->type = MTD_NANDFLASH;	mtd->flags = MTD_CAP_NANDFLASH;	mtd->owner = THIS_MODULE;	mtd->ecctype = MTD_ECC_NONE;	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->readv = NULL;	mtd->writev = nand_writev;	mtd->sync = nand_sync;	mtd->lock = NULL;	mtd->unlock = NULL;	mtd->suspend = NULL;	mtd->resume = NULL;	/* Return happy */	return 0;}#if 0#ifdef MODULEMODULE_PARM(sizeInMB, "i");__setup("sizeInMB=",sizeInMB);#endif#endif/* * Define partitions for flash devices */static struct mtd_partition nandemul_partition[] ={	{ name: "NANDemul partition 1",	  offset:  0,	  size: 0 },};static int nPartitions = sizeof(nandemul_partition)/sizeof(nandemul_partition[0]);/* * Main initialization routine */int __init nandemul_init (void){	// Do the nand init	nand_scan(&nandemul_mtd,1);	nandemul_Initialise();	// Build the partition table	nandemul_partition[0].size = sizeInMB * 1024 * 1024;	// Register the partition	add_mtd_partitions(&nandemul_mtd,nandemul_partition,nPartitions);	return 0;}module_init(nandemul_init);/* * Clean up routine */#ifdef MODULEstatic void __exit nandemul_cleanup (void){	nandemul_DeInitialise();	/* Unregister partitions */	del_mtd_partitions(&nandemul_mtd);	/* Unregister the device */	del_mtd_device (&nandemul_mtd);}module_exit(nandemul_cleanup);#endifMODULE_LICENSE("GPL");MODULE_AUTHOR("Charles Manning <manningc@aleph1.co.uk>");MODULE_DESCRIPTION("NAND emulated in RAM");