[MTD] OneNAND: Add missing files

/*

 *  linux/drivers/mtd/onenand/onenand_bbt.c

 *

 *  Bad Block Table support for the OneNAND driver

 *

 *  Copyright(c) 2005 Samsung Electronics

 *  Kyungmin Park <kyungmin.park@samsung.com>

 *

 *  Derived from nand_bbt.c

 *

 *  TODO:

 *    Split BBT core and chip specific BBT.

 */

#include <linux/slab.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/onenand.h>

#include <linux/mtd/compatmac.h>

/**

 * check_short_pattern - [GENERIC] check if a pattern is in the buffer

 * @param buf		the buffer to search

 * @param len		the length of buffer to search

 * @param paglen	the pagelength

 * @param td		search pattern descriptor

 *

 * Check for a pattern at the given place. Used to search bad block

 * tables and good / bad block identifiers. Same as check_pattern, but

 * no optional empty check and the pattern is expected to start

 * at offset 0.

 *

 */

static int check_short_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)

{

	int i;

	uint8_t *p = buf;

	/* Compare the pattern */

	for (i = 0; i < td->len; i++) {

		if (p[i] != td->pattern[i])

			return -1;

	}

        return 0;

}

/**

 * create_bbt - [GENERIC] Create a bad block table by scanning the device

 * @param mtd		MTD device structure

 * @param buf		temporary buffer

 * @param bd		descriptor for the good/bad block search pattern

 * @param chip		create the table for a specific chip, -1 read all chips.

 *              Applies only if NAND_BBT_PERCHIP option is set

 *

 * Create a bad block table by scanning the device

 * for the given good/bad block identify pattern

 */

static int create_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd, int chip)

{

	struct onenand_chip *this = mtd->priv;

	struct bbm_info *bbm = this->bbm;

	int i, j, numblocks, len, scanlen;

	int startblock;

	loff_t from;

	size_t readlen, ooblen;

	printk(KERN_INFO "Scanning device for bad blocks\n");

	len = 1;

	/* We need only read few bytes from the OOB area */

	scanlen = ooblen = 0;

	readlen = bd->len;

	/* chip == -1 case only */

	/* Note that numblocks is 2 * (real numblocks) here;

	 * see i += 2 below as it makses shifting and masking less painful

	 */

	numblocks = mtd->size >> (bbm->bbt_erase_shift - 1);

	startblock = 0;

	from = 0;

	for (i = startblock; i < numblocks; ) {

		int ret;

		for (j = 0; j < len; j++) {

			size_t retlen;

			/* No need to read pages fully,

			 * just read required OOB bytes */

			ret = mtd->read_oob(mtd, from + j * mtd->oobblock + bd->offs,

						readlen, &retlen, &buf[0]);

			if (ret)

				return ret;

			if (check_short_pattern(&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {

				bbm->bbt[i >> 3] |= 0x03 << (i & 0x6);

				printk(KERN_WARNING "Bad eraseblock %d at 0x%08x\n",

					i >> 1, (unsigned int) from);

				break;

			}

		}

		i += 2;

		from += (1 << bbm->bbt_erase_shift);

	}

	return 0;

}

/**

 * onenand_memory_bbt - [GENERIC] create a memory based bad block table

 * @param mtd		MTD device structure

 * @param bd		descriptor for the good/bad block search pattern

 *

 * The function creates a memory based bbt by scanning the device

 * for manufacturer / software marked good / bad blocks

 */

static inline int onenand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd)

{

	unsigned char data_buf[MAX_ONENAND_PAGESIZE];

        bd->options &= ~NAND_BBT_SCANEMPTY;

        return create_bbt(mtd, data_buf, bd, -1);

}

/**

 * onenand_isbad_bbt - [OneNAND Interface] Check if a block is bad

 * @param mtd		MTD device structure

 * @param offs		offset in the device

 * @param allowbbt	allow access to bad block table region

 */

static int onenand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)

{

	struct onenand_chip *this = mtd->priv;

	struct bbm_info *bbm = this->bbm;

	int block;

	uint8_t res;

	/* Get block number * 2 */

	block = (int) (offs >> (bbm->bbt_erase_shift - 1));

	res = (bbm->bbt[block >> 3] >> (block & 0x06)) & 0x03;

	DEBUG(MTD_DEBUG_LEVEL2, "onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n",

		(unsigned int) offs, block >> 1, res);

	switch ((int) res) {

	case 0x00:	return 0;

	case 0x01:	return 1;

	case 0x02:	return allowbbt ? 0 : 1;

	}

	return 1;

}

/**

 * onenand_scan_bbt - [OneNAND Interface] scan, find, read and maybe create bad block table(s)

 * @param mtd		MTD device structure

 * @param bd		descriptor for the good/bad block search pattern

 *

 * The function checks, if a bad block table(s) is/are already

 * available. If not it scans the device for manufacturer

 * marked good / bad blocks and writes the bad block table(s) to

 * the selected place.

 *

 * The bad block table memory is allocated here. It must be freed

 * by calling the onenand_free_bbt function.

 *

 */

int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)

{

	struct onenand_chip *this = mtd->priv;

	struct bbm_info *bbm = this->bbm;

	int len, ret = 0;

	len = mtd->size >> (this->erase_shift + 2);

	/* Allocate memory (2bit per block) */

	bbm->bbt = kmalloc(len, GFP_KERNEL);

	if (!bbm->bbt) {

		printk(KERN_ERR "onenand_scan_bbt: Out of memory\n");

		return -ENOMEM;

	}

	/* Clear the memory bad block table */

	memset(bbm->bbt, 0x00, len);

	/* Set the bad block position */

	bbm->badblockpos = ONENAND_BADBLOCK_POS;

	/* Set erase shift */

	bbm->bbt_erase_shift = this->erase_shift;

	if (!bbm->isbad_bbt)

		bbm->isbad_bbt = onenand_isbad_bbt;

	/* Scan the device to build a memory based bad block table */

	if ((ret = onenand_memory_bbt(mtd, bd))) {

		printk(KERN_ERR "onenand_scan_bbt: Can't scan flash and build the RAM-based BBT\n");

		kfree(bbm->bbt);

		bbm->bbt = NULL;

	}

	return ret;

}

/*

 * Define some generic bad / good block scan pattern which are used

 * while scanning a device for factory marked good / bad blocks.

 */

static uint8_t scan_ff_pattern[] = { 0xff, 0xff };

static struct nand_bbt_descr largepage_memorybased = {

	.options = 0,

	.offs = 0,

	.len = 2,

	.pattern = scan_ff_pattern,

};

/**

 * onenand_default_bbt - [OneNAND Interface] Select a default bad block table for the device

 * @param mtd		MTD device structure

 *

 * This function selects the default bad block table

 * support for the device and calls the onenand_scan_bbt function

 */

int onenand_default_bbt(struct mtd_info *mtd)

{

	struct onenand_chip *this = mtd->priv;

	struct bbm_info *bbm;

	this->bbm = kmalloc(sizeof(struct bbm_info), GFP_KERNEL);

	if (!this->bbm)

		return -ENOMEM;

	bbm = this->bbm;

	memset(bbm, 0, sizeof(struct bbm_info));

	/* 1KB page has same configuration as 2KB page */

	if (!bbm->badblock_pattern)

		bbm->badblock_pattern = &largepage_memorybased;

	return onenand_scan_bbt(mtd, bbm->badblock_pattern);

}

EXPORT_SYMBOL(onenand_scan_bbt);

EXPORT_SYMBOL(onenand_default_bbt);

/*

 *  linux/include/linux/mtd/bbm.h

 *

 *  NAND family Bad Block Management (BBM) header file

 *    - Bad Block Table (BBT) implementation

 *

 *  Copyright (c) 2005 Samsung Electronics

 *  Kyungmin Park <kyungmin.park@samsung.com>

 *

 *  Copyright (c) 2000-2005

 *  Thomas Gleixner <tglx@linuxtronix.de>

 *

 */

#ifndef __LINUX_MTD_BBM_H

#define __LINUX_MTD_BBM_H

/* The maximum number of NAND chips in an array */

#define NAND_MAX_CHIPS		8

/**

 * struct nand_bbt_descr - bad block table descriptor

 * @param options	options for this descriptor

 * @param pages		the page(s) where we find the bbt, used with

 * 			option BBT_ABSPAGE when bbt is searched,

 * 			then we store the found bbts pages here.

 *			Its an array and supports up to 8 chips now

 * @param offs		offset of the pattern in the oob area of the page

 * @param veroffs	offset of the bbt version counter in the oob are of the page

 * @param version	version read from the bbt page during scan

 * @param len		length of the pattern, if 0 no pattern check is performed

 * @param maxblocks	maximum number of blocks to search for a bbt. This number of

 *			blocks is reserved at the end of the device 

 *			where the tables are written.

 * @param reserved_block_code	if non-0, this pattern denotes a reserved

 *			(rather than bad) block in the stored bbt

 * @param pattern	pattern to identify bad block table or factory marked

 *			good / bad blocks, can be NULL, if len = 0

 *

 * Descriptor for the bad block table marker and the descriptor for the

 * pattern which identifies good and bad blocks. The assumption is made

 * that the pattern and the version count are always located in the oob area

 * of the first block.

 */

struct nand_bbt_descr {

	int options;

	int pages[NAND_MAX_CHIPS];

	int offs;

	int veroffs;

	uint8_t version[NAND_MAX_CHIPS];

	int len;

	int maxblocks;

	int reserved_block_code;

	uint8_t *pattern;

};

/* Options for the bad block table descriptors */

/* The number of bits used per block in the bbt on the device */

#define NAND_BBT_NRBITS_MSK	0x0000000F

#define NAND_BBT_1BIT		0x00000001

#define NAND_BBT_2BIT		0x00000002

#define NAND_BBT_4BIT		0x00000004

#define NAND_BBT_8BIT		0x00000008

/* The bad block table is in the last good block of the device */

#define NAND_BBT_LASTBLOCK	0x00000010

/* The bbt is at the given page, else we must scan for the bbt */

#define NAND_BBT_ABSPAGE	0x00000020

/* The bbt is at the given page, else we must scan for the bbt */

#define NAND_BBT_SEARCH		0x00000040

/* bbt is stored per chip on multichip devices */

#define NAND_BBT_PERCHIP	0x00000080

/* bbt has a version counter at offset veroffs */

#define NAND_BBT_VERSION	0x00000100

/* Create a bbt if none axists */

#define NAND_BBT_CREATE		0x00000200

/* Search good / bad pattern through all pages of a block */

#define NAND_BBT_SCANALLPAGES	0x00000400

/* Scan block empty during good / bad block scan */

#define NAND_BBT_SCANEMPTY	0x00000800

/* Write bbt if neccecary */

#define NAND_BBT_WRITE		0x00001000

/* Read and write back block contents when writing bbt */

#define NAND_BBT_SAVECONTENT	0x00002000

/* Search good / bad pattern on the first and the second page */

#define NAND_BBT_SCAN2NDPAGE	0x00004000

/* The maximum number of blocks to scan for a bbt */

#define NAND_BBT_SCAN_MAXBLOCKS	4

/*

 * Constants for oob configuration

 */

#define ONENAND_BADBLOCK_POS	0

/**

 * struct bbt_info - [GENERIC] Bad Block Table data structure

 * @param bbt_erase_shift	[INTERN] number of address bits in a bbt entry

 * @param badblockpos		[INTERN] position of the bad block marker in the oob area

 * @param bbt			[INTERN] bad block table pointer

 * @param badblock_pattern	[REPLACEABLE] bad block scan pattern used for initial bad block scan

 * @param priv			[OPTIONAL] pointer to private bbm date

 */

struct bbm_info {

	int bbt_erase_shift;

	int badblockpos;

	int options;

	uint8_t *bbt;

	int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);

	/* TODO Add more NAND specific fileds */

	struct nand_bbt_descr *badblock_pattern;

	void *priv;

};

/* OneNAND BBT interface */

extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);

extern int onenand_default_bbt(struct mtd_info *mtd);

#endif	/* __LINUX_MTD_BBM_H */