[linux-2.6-block.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>

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