[net-next-2.6.git] / drivers / mtd / onenand / onenand_bbt.c

/*
 *  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>

extern int onenand_do_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
			       size_t *retlen, u_char *buf);

/**
 * 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 = onenand_do_read_oob(mtd, from + j * mtd->writesize + bd->offs,
						  readlen, &retlen, &buf[0]);

			if (ret)
				return ret;

			if (check_short_pattern(&buf[j * scanlen], scanlen, mtd->writesize, bd)) {
				bbm->bbt[i >> 3] |= 0x03 << (i & 0x6);
				printk(KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
					i >> 1, (unsigned int) from);
				mtd->ecc_stats.badblocks++;
				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)
{
	struct onenand_chip *this = mtd->priv;

        bd->options &= ~NAND_BBT_SCANEMPTY;
	return create_bbt(mtd, this->page_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);
Commit	Line	Data
87590e26 KP	1	/*
	2	* linux/drivers/mtd/onenand/onenand_bbt.c
	3	*
	4	* Bad Block Table support for the OneNAND driver
	5	*
	6	* Copyright(c) 2005 Samsung Electronics
	7	* Kyungmin Park <kyungmin.park@samsung.com>
	8	*
	9	* Derived from nand_bbt.c
	10	*
	11	* TODO:
	12	* Split BBT core and chip specific BBT.
	13	*/
	14
	15	#include <linux/slab.h>
	16	#include <linux/mtd/mtd.h>
	17	#include <linux/mtd/onenand.h>
	18	#include <linux/mtd/compatmac.h>
	19
8593fbc6 TG	20	extern int onenand_do_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
	21	size_t retlen, u_char buf);
	22
87590e26 KP	23	/**
	24	* check_short_pattern - [GENERIC] check if a pattern is in the buffer
	25	* @param buf the buffer to search
	26	* @param len the length of buffer to search
	27	* @param paglen the pagelength
	28	* @param td search pattern descriptor
	29	*
	30	* Check for a pattern at the given place. Used to search bad block
	31	* tables and good / bad block identifiers. Same as check_pattern, but
	32	* no optional empty check and the pattern is expected to start
	33	* at offset 0.
	34	*
	35	*/
	36	static int check_short_pattern(uint8_t buf, int len, int paglen, struct nand_bbt_descr td)
	37	{
	38	int i;
	39	uint8_t *p = buf;
	40
	41	/* Compare the pattern */
	42	for (i = 0; i < td->len; i++) {
	43	if (p[i] != td->pattern[i])
	44	return -1;
	45	}
	46	return 0;
	47	}
	48
	49	/**
	50	* create_bbt - [GENERIC] Create a bad block table by scanning the device
	51	* @param mtd MTD device structure
	52	* @param buf temporary buffer
	53	* @param bd descriptor for the good/bad block search pattern
	54	* @param chip create the table for a specific chip, -1 read all chips.
	55	* Applies only if NAND_BBT_PERCHIP option is set
	56	*
	57	* Create a bad block table by scanning the device
	58	* for the given good/bad block identify pattern
	59	*/
	60	static int create_bbt(struct mtd_info mtd, uint8_t buf, struct nand_bbt_descr *bd, int chip)
	61	{
	62	struct onenand_chip *this = mtd->priv;
	63	struct bbm_info *bbm = this->bbm;
	64	int i, j, numblocks, len, scanlen;
	65	int startblock;
	66	loff_t from;
	67	size_t readlen, ooblen;
	68
	69	printk(KERN_INFO "Scanning device for bad blocks\n");
	70
	71	len = 1;
	72
	73	/* We need only read few bytes from the OOB area */
	74	scanlen = ooblen = 0;
	75	readlen = bd->len;
	76
	77	/* chip == -1 case only */
	78	/* Note that numblocks is 2 * (real numblocks) here;
	79	* see i += 2 below as it makses shifting and masking less painful
	80	*/
	81	numblocks = mtd->size >> (bbm->bbt_erase_shift - 1);
	82	startblock = 0;
	83	from = 0;
	84
	85	for (i = startblock; i < numblocks; ) {
	86	int ret;
87
88	for (j = 0; j < len; j++) {
89	size_t retlen;
90
91	/* No need to read pages fully,
92	* just read required OOB bytes */
8593fbc6 TG	93	ret = onenand_do_read_oob(mtd, from + j * mtd->writesize + bd->offs,
8593fbc6 TG	94	readlen, &retlen, &buf[0]);
87590e26 KP	95
	96	if (ret)
	97	return ret;
	98
28318776	99	if (check_short_pattern(&buf[j * scanlen], scanlen, mtd->writesize, bd)) {
87590e26 KP	100	bbm->bbt[i >> 3] \|= 0x03 << (i & 0x6);
	101	printk(KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
	102	i >> 1, (unsigned int) from);
f4f91ac3	103	mtd->ecc_stats.badblocks++;
87590e26 KP	104	break;
	105	}
	106	}
	107	i += 2;
	108	from += (1 << bbm->bbt_erase_shift);
	109	}
	110
	111	return 0;
	112	}
	113
	114
	115	/**
	116	* onenand_memory_bbt - [GENERIC] create a memory based bad block table
	117	* @param mtd MTD device structure
	118	* @param bd descriptor for the good/bad block search pattern
	119	*
	120	* The function creates a memory based bbt by scanning the device
	121	* for manufacturer / software marked good / bad blocks
	122	*/
	123	static inline int onenand_memory_bbt (struct mtd_info mtd, struct nand_bbt_descr bd)
	124	{
532a37cf	125	struct onenand_chip *this = mtd->priv;
87590e26 KP	126
87590e26 KP	127	bd->options &= ~NAND_BBT_SCANEMPTY;
532a37cf	128	return create_bbt(mtd, this->page_buf, bd, -1);
87590e26 KP	129	}
	130
	131	/**
	132	* onenand_isbad_bbt - [OneNAND Interface] Check if a block is bad
	133	* @param mtd MTD device structure
	134	* @param offs offset in the device
	135	* @param allowbbt allow access to bad block table region
	136	*/
	137	static int onenand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
	138	{
	139	struct onenand_chip *this = mtd->priv;
	140	struct bbm_info *bbm = this->bbm;
	141	int block;
	142	uint8_t res;
	143
	144	/* Get block number * 2 */
	145	block = (int) (offs >> (bbm->bbt_erase_shift - 1));
	146	res = (bbm->bbt[block >> 3] >> (block & 0x06)) & 0x03;
	147
	148	DEBUG(MTD_DEBUG_LEVEL2, "onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n",
	149	(unsigned int) offs, block >> 1, res);
	150
	151	switch ((int) res) {
	152	case 0x00: return 0;
	153	case 0x01: return 1;
	154	case 0x02: return allowbbt ? 0 : 1;
	155	}
	156
	157	return 1;
	158	}
	159
	160	/**
	161	* onenand_scan_bbt - [OneNAND Interface] scan, find, read and maybe create bad block table(s)
	162	* @param mtd MTD device structure
	163	* @param bd descriptor for the good/bad block search pattern
	164	*
	165	* The function checks, if a bad block table(s) is/are already
	166	* available. If not it scans the device for manufacturer
	167	* marked good / bad blocks and writes the bad block table(s) to
	168	* the selected place.
	169	*
	170	* The bad block table memory is allocated here. It must be freed
	171	* by calling the onenand_free_bbt function.
	172	*
	173	*/
	174	int onenand_scan_bbt(struct mtd_info mtd, struct nand_bbt_descr bd)
	175	{
	176	struct onenand_chip *this = mtd->priv;
	177	struct bbm_info *bbm = this->bbm;
	178	int len, ret = 0;
	179
	180	len = mtd->size >> (this->erase_shift + 2);
	181	/* Allocate memory (2bit per block) */
	182	bbm->bbt = kmalloc(len, GFP_KERNEL);
	183	if (!bbm->bbt) {
	184	printk(KERN_ERR "onenand_scan_bbt: Out of memory\n");
	185	return -ENOMEM;
	186	}
	187	/* Clear the memory bad block table */
	188	memset(bbm->bbt, 0x00, len);
	189
	190	/* Set the bad block position */
	191	bbm->badblockpos = ONENAND_BADBLOCK_POS;
	192
193	/* Set erase shift */
194	bbm->bbt_erase_shift = this->erase_shift;
195
196	if (!bbm->isbad_bbt)
197	bbm->isbad_bbt = onenand_isbad_bbt;
198
199	/* Scan the device to build a memory based bad block table */
200	if ((ret = onenand_memory_bbt(mtd, bd))) {
201	printk(KERN_ERR "onenand_scan_bbt: Can't scan flash and build the RAM-based BBT\n");
202	kfree(bbm->bbt);
203	bbm->bbt = NULL;
204	}
205
206	return ret;
207	}
208
209	/*
210	* Define some generic bad / good block scan pattern which are used
211	* while scanning a device for factory marked good / bad blocks.
212	*/
213	static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
214
215	static struct nand_bbt_descr largepage_memorybased = {
216	.options = 0,
217	.offs = 0,
218	.len = 2,
219	.pattern = scan_ff_pattern,
220	};
221
222	/**
223	* onenand_default_bbt - [OneNAND Interface] Select a default bad block table for the device
224	* @param mtd MTD device structure
225	*
226	* This function selects the default bad block table
227	* support for the device and calls the onenand_scan_bbt function
228	*/
229	int onenand_default_bbt(struct mtd_info *mtd)
230	{
231	struct onenand_chip *this = mtd->priv;
232	struct bbm_info *bbm;
233
234	this->bbm = kmalloc(sizeof(struct bbm_info), GFP_KERNEL);
235	if (!this->bbm)
236	return -ENOMEM;
237
238	bbm = this->bbm;
239
240	memset(bbm, 0, sizeof(struct bbm_info));
241
242	/* 1KB page has same configuration as 2KB page */
243	if (!bbm->badblock_pattern)
244	bbm->badblock_pattern = &largepage_memorybased;
245
246	return onenand_scan_bbt(mtd, bbm->badblock_pattern);
247	}
248
249	EXPORT_SYMBOL(onenand_scan_bbt);
250	EXPORT_SYMBOL(onenand_default_bbt);