[linux.git] / drivers / mtd / ssfdc.c

/*
 * Linux driver for SSFDC Flash Translation Layer (Read only)
 * (c) 2005 Eptar srl
 * Author: Claudio Lanconelli <[email protected]>
 *
 * Based on NTFL and MTDBLOCK_RO drivers
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/hdreg.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/blktrans.h>

struct ssfdcr_record {
	struct mtd_blktrans_dev mbd;
	int usecount;
	unsigned char heads;
	unsigned char sectors;
	unsigned short cylinders;
	int cis_block;			/* block n. containing CIS/IDI */
	int erase_size;			/* phys_block_size */
	unsigned short *logic_block_map; /* all zones (max 8192 phys blocks on
					    the 128MiB) */
	int map_len;			/* n. phys_blocks on the card */
};

#define SSFDCR_MAJOR		257
#define SSFDCR_PARTN_BITS	3

#define SECTOR_SIZE		512
#define SECTOR_SHIFT		9
#define OOB_SIZE		16

#define MAX_LOGIC_BLK_PER_ZONE	1000
#define MAX_PHYS_BLK_PER_ZONE	1024

#define KiB(x)	( (x) * 1024L )
#define MiB(x)	( KiB(x) * 1024L )

/** CHS Table
		1MiB	2MiB	4MiB	8MiB	16MiB	32MiB	64MiB	128MiB
NCylinder	125	125	250	250	500	500	500	500
NHead		4	4	4	4	4	8	8	16
NSector		4	8	8	16	16	16	32	32
SumSector	2,000	4,000	8,000	16,000	32,000	64,000	128,000	256,000
SectorSize	512	512	512	512	512	512	512	512
**/

typedef struct {
	unsigned long size;
	unsigned short cyl;
	unsigned char head;
	unsigned char sec;
} chs_entry_t;

/* Must be ordered by size */
static const chs_entry_t chs_table[] = {
	{ MiB(  1), 125,  4,  4 },
	{ MiB(  2), 125,  4,  8 },
	{ MiB(  4), 250,  4,  8 },
	{ MiB(  8), 250,  4, 16 },
	{ MiB( 16), 500,  4, 16 },
	{ MiB( 32), 500,  8, 16 },
	{ MiB( 64), 500,  8, 32 },
	{ MiB(128), 500, 16, 32 },
	{ 0 },
};

static int get_chs(unsigned long size, unsigned short *cyl, unsigned char *head,
			unsigned char *sec)
{
	int k;
	int found = 0;

	k = 0;
	while (chs_table[k].size > 0 && size > chs_table[k].size)
		k++;

	if (chs_table[k].size > 0) {
		if (cyl)
			*cyl = chs_table[k].cyl;
		if (head)
			*head = chs_table[k].head;
		if (sec)
			*sec = chs_table[k].sec;
		found = 1;
	}

	return found;
}

/* These bytes are the signature for the CIS/IDI sector */
static const uint8_t cis_numbers[] = {
	0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
};

/* Read and check for a valid CIS sector */
static int get_valid_cis_sector(struct mtd_info *mtd)
{
	int ret, k, cis_sector;
	size_t retlen;
	loff_t offset;
	uint8_t *sect_buf;

	cis_sector = -1;

	sect_buf = kmalloc(SECTOR_SIZE, GFP_KERNEL);
	if (!sect_buf)
		goto out;

	/*
	 * Look for CIS/IDI sector on the first GOOD block (give up after 4 bad
	 * blocks). If the first good block doesn't contain CIS number the flash
	 * is not SSFDC formatted
	 */
	for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) {
		if (!mtd->block_isbad(mtd, offset)) {
			ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen,
				sect_buf);

			/* CIS pattern match on the sector buffer */
			if (ret < 0 || retlen != SECTOR_SIZE) {
				printk(KERN_WARNING
					"SSFDC_RO:can't read CIS/IDI sector\n");
			} else if (!memcmp(sect_buf, cis_numbers,
					sizeof(cis_numbers))) {
				/* Found */
				cis_sector = (int)(offset >> SECTOR_SHIFT);
			} else {
				DEBUG(MTD_DEBUG_LEVEL1,
					"SSFDC_RO: CIS/IDI sector not found"
					" on %s (mtd%d)\n", mtd->name,
					mtd->index);
			}
			break;
		}
	}

	kfree(sect_buf);
 out:
	return cis_sector;
}

/* Read physical sector (wrapper to MTD_READ) */
static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf,
				int sect_no)
{
	int ret;
	size_t retlen;
	loff_t offset = (loff_t)sect_no << SECTOR_SHIFT;

	ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
	if (ret < 0 || retlen != SECTOR_SIZE)
		return -1;

	return 0;
}

/* Read redundancy area (wrapper to MTD_READ_OOB */
static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf)
{
	struct mtd_oob_ops ops;
	int ret;

	ops.mode = MTD_OOB_RAW;
	ops.ooboffs = 0;
	ops.ooblen = OOB_SIZE;
	ops.oobbuf = buf;
	ops.datbuf = NULL;

	ret = mtd->read_oob(mtd, offs, &ops);
	if (ret < 0 || ops.oobretlen != OOB_SIZE)
		return -1;

	return 0;
}

/* Parity calculator on a word of n bit size */
static int get_parity(int number, int size)
{
 	int k;
	int parity;

	parity = 1;
	for (k = 0; k < size; k++) {
		parity += (number >> k);
		parity &= 1;
	}
	return parity;
}

/* Read and validate the logical block address field stored in the OOB */
static int get_logical_address(uint8_t *oob_buf)
{
	int block_address, parity;
	int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
	int j;
	int ok = 0;

	/*
	 * Look for the first valid logical address
	 * Valid address has fixed pattern on most significant bits and
	 * parity check
	 */
	for (j = 0; j < ARRAY_SIZE(offset); j++) {
		block_address = ((int)oob_buf[offset[j]] << 8) |
			oob_buf[offset[j]+1];

		/* Check for the signature bits in the address field (MSBits) */
		if ((block_address & ~0x7FF) == 0x1000) {
			parity = block_address & 0x01;
			block_address &= 0x7FF;
			block_address >>= 1;

			if (get_parity(block_address, 10) != parity) {
				DEBUG(MTD_DEBUG_LEVEL0,
					"SSFDC_RO: logical address field%d"
					"parity error(0x%04X)\n", j+1,
					block_address);
			} else {
				ok = 1;
				break;
			}
		}
	}

	if (!ok)
		block_address = -2;

	DEBUG(MTD_DEBUG_LEVEL3, "SSFDC_RO: get_logical_address() %d\n",
		block_address);

	return block_address;
}

/* Build the logic block map */
static int build_logical_block_map(struct ssfdcr_record *ssfdc)
{
	unsigned long offset;
	uint8_t oob_buf[OOB_SIZE];
	int ret, block_address, phys_block;
	struct mtd_info *mtd = ssfdc->mbd.mtd;

	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: build_block_map() nblks=%d (%luK)\n",
	      ssfdc->map_len,
	      (unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024);

	/* Scan every physical block, skip CIS block */
	for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len;
			phys_block++) {
		offset = (unsigned long)phys_block * ssfdc->erase_size;
		if (mtd->block_isbad(mtd, offset))
			continue;	/* skip bad blocks */

		ret = read_raw_oob(mtd, offset, oob_buf);
		if (ret < 0) {
			DEBUG(MTD_DEBUG_LEVEL0,
				"SSFDC_RO: mtd read_oob() failed at %lu\n",
				offset);
			return -1;
		}
		block_address = get_logical_address(oob_buf);

		/* Skip invalid addresses */
		if (block_address >= 0 &&
				block_address < MAX_LOGIC_BLK_PER_ZONE) {
			int zone_index;

			zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE;
			block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE;
			ssfdc->logic_block_map[block_address] =
				(unsigned short)phys_block;

			DEBUG(MTD_DEBUG_LEVEL2,
				"SSFDC_RO: build_block_map() phys_block=%d,"
				"logic_block_addr=%d, zone=%d\n",
				phys_block, block_address, zone_index);
		}
	}
	return 0;
}

static void ssfdcr_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
	struct ssfdcr_record *ssfdc;
	int cis_sector;

	/* Check for small page NAND flash */
	if (mtd->type != MTD_NANDFLASH || mtd->oobsize != OOB_SIZE ||
	    mtd->size > UINT_MAX)
		return;

	/* Check for SSDFC format by reading CIS/IDI sector */
	cis_sector = get_valid_cis_sector(mtd);
	if (cis_sector == -1)
		return;

	ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL);
	if (!ssfdc) {
		printk(KERN_WARNING
			"SSFDC_RO: out of memory for data structures\n");
		return;
	}

	ssfdc->mbd.mtd = mtd;
	ssfdc->mbd.devnum = -1;
	ssfdc->mbd.tr = tr;
	ssfdc->mbd.readonly = 1;

	ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT);
	ssfdc->erase_size = mtd->erasesize;
	ssfdc->map_len = (u32)mtd->size / mtd->erasesize;

	DEBUG(MTD_DEBUG_LEVEL1,
		"SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n",
		ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len,
		DIV_ROUND_UP(ssfdc->map_len, MAX_PHYS_BLK_PER_ZONE));

	/* Set geometry */
	ssfdc->heads = 16;
	ssfdc->sectors = 32;
	get_chs(mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors);
	ssfdc->cylinders = (unsigned short)(((u32)mtd->size >> SECTOR_SHIFT) /
			((long)ssfdc->sectors * (long)ssfdc->heads));

	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n",
		ssfdc->cylinders, ssfdc->heads , ssfdc->sectors,
		(long)ssfdc->cylinders * (long)ssfdc->heads *
		(long)ssfdc->sectors);

	ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders *
				(long)ssfdc->sectors;

	/* Allocate logical block map */
	ssfdc->logic_block_map = kmalloc(sizeof(ssfdc->logic_block_map[0]) *
					 ssfdc->map_len, GFP_KERNEL);
	if (!ssfdc->logic_block_map) {
		printk(KERN_WARNING
			"SSFDC_RO: out of memory for data structures\n");
		goto out_err;
	}
	memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) *
		ssfdc->map_len);

	/* Build logical block map */
	if (build_logical_block_map(ssfdc) < 0)
		goto out_err;

	/* Register device + partitions */
	if (add_mtd_blktrans_dev(&ssfdc->mbd))
		goto out_err;

	printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n",
		ssfdc->mbd.devnum + 'a', mtd->index, mtd->name);
	return;

out_err:
	kfree(ssfdc->logic_block_map);
        kfree(ssfdc);
}

static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev)
{
	struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;

	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: remove_dev (i=%d)\n", dev->devnum);

	del_mtd_blktrans_dev(dev);
	kfree(ssfdc->logic_block_map);
}

static int ssfdcr_readsect(struct mtd_blktrans_dev *dev,
				unsigned long logic_sect_no, char *buf)
{
	struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
	int sectors_per_block, offset, block_address;

	sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT;
	offset = (int)(logic_sect_no % sectors_per_block);
	block_address = (int)(logic_sect_no / sectors_per_block);

	DEBUG(MTD_DEBUG_LEVEL3,
		"SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d,"
		" block_addr=%d\n", logic_sect_no, sectors_per_block, offset,
		block_address);

	if (block_address >= ssfdc->map_len)
		BUG();

	block_address = ssfdc->logic_block_map[block_address];

	DEBUG(MTD_DEBUG_LEVEL3,
		"SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n",
		block_address);

	if (block_address < 0xffff) {
		unsigned long sect_no;

		sect_no = (unsigned long)block_address * sectors_per_block +
				offset;

		DEBUG(MTD_DEBUG_LEVEL3,
			"SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n",
			sect_no);

		if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0)
			return -EIO;
	} else {
		memset(buf, 0xff, SECTOR_SIZE);
	}

	return 0;
}

static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev,  struct hd_geometry *geo)
{
	struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;

	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n",
			ssfdc->cylinders, ssfdc->heads, ssfdc->sectors);

	geo->heads = ssfdc->heads;
	geo->sectors = ssfdc->sectors;
	geo->cylinders = ssfdc->cylinders;

	return 0;
}

/****************************************************************************
 *
 * Module stuff
 *
 ****************************************************************************/

static struct mtd_blktrans_ops ssfdcr_tr = {
	.name		= "ssfdc",
	.major		= SSFDCR_MAJOR,
	.part_bits	= SSFDCR_PARTN_BITS,
	.blksize	= SECTOR_SIZE,
	.getgeo		= ssfdcr_getgeo,
	.readsect	= ssfdcr_readsect,
	.add_mtd	= ssfdcr_add_mtd,
	.remove_dev	= ssfdcr_remove_dev,
	.owner		= THIS_MODULE,
};

static int __init init_ssfdcr(void)
{
	printk(KERN_INFO "SSFDC read-only Flash Translation layer\n");

	return register_mtd_blktrans(&ssfdcr_tr);
}

static void __exit cleanup_ssfdcr(void)
{
	deregister_mtd_blktrans(&ssfdcr_tr);
}

module_init(init_ssfdcr);
module_exit(cleanup_ssfdcr);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Claudio Lanconelli <[email protected]>");
MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card");
Commit	Line	Data
51197abf CL	1	/*
	2	* Linux driver for SSFDC Flash Translation Layer (Read only)
	3	* (c) 2005 Eptar srl
	4	* Author: Claudio Lanconelli <[email protected]>
	5	*
	6	* Based on NTFL and MTDBLOCK_RO drivers
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
51197abf CL	13	#include <linux/kernel.h>
	14	#include <linux/module.h>
	15	#include <linux/init.h>
	16	#include <linux/slab.h>
	17	#include <linux/hdreg.h>
	18	#include <linux/mtd/mtd.h>
	19	#include <linux/mtd/nand.h>
	20	#include <linux/mtd/blktrans.h>
	21
	22	struct ssfdcr_record {
	23	struct mtd_blktrans_dev mbd;
	24	int usecount;
	25	unsigned char heads;
	26	unsigned char sectors;
	27	unsigned short cylinders;
	28	int cis_block; /* block n. containing CIS/IDI */
	29	int erase_size; /* phys_block_size */
	30	unsigned short logic_block_map; / all zones (max 8192 phys blocks on
9a05eded	31	the 128MiB) */
51197abf CL	32	int map_len; /* n. phys_blocks on the card */
	33	};
	34
	35	#define SSFDCR_MAJOR 257
	36	#define SSFDCR_PARTN_BITS 3
	37
	38	#define SECTOR_SIZE 512
	39	#define SECTOR_SHIFT 9
	40	#define OOB_SIZE 16
	41
	42	#define MAX_LOGIC_BLK_PER_ZONE 1000
	43	#define MAX_PHYS_BLK_PER_ZONE 1024
	44
9a05eded DW	45	#define KiB(x) ( (x) * 1024L )
9a05eded DW	46	#define MiB(x) ( KiB(x) * 1024L )
51197abf CL	47
51197abf CL	48	/** CHS Table
9a05eded	49	1MiB 2MiB 4MiB 8MiB 16MiB 32MiB 64MiB 128MiB
51197abf CL	50	NCylinder 125 125 250 250 500 500 500 500
	51	NHead 4 4 4 4 4 8 8 16
	52	NSector 4 8 8 16 16 16 32 32
	53	SumSector 2,000 4,000 8,000 16,000 32,000 64,000 128,000 256,000
	54	SectorSize 512 512 512 512 512 512 512 512
	55	**/
	56
	57	typedef struct {
	58	unsigned long size;
	59	unsigned short cyl;
	60	unsigned char head;
	61	unsigned char sec;
	62	} chs_entry_t;
	63
	64	/* Must be ordered by size */
	65	static const chs_entry_t chs_table[] = {
9a05eded DW	66	{ MiB( 1), 125, 4, 4 },
	67	{ MiB( 2), 125, 4, 8 },
	68	{ MiB( 4), 250, 4, 8 },
	69	{ MiB( 8), 250, 4, 16 },
	70	{ MiB( 16), 500, 4, 16 },
	71	{ MiB( 32), 500, 8, 16 },
	72	{ MiB( 64), 500, 8, 32 },
	73	{ MiB(128), 500, 16, 32 },
51197abf CL	74	{ 0 },
	75	};
	76
	77	static int get_chs(unsigned long size, unsigned short cyl, unsigned char head,
	78	unsigned char *sec)
	79	{
	80	int k;
	81	int found = 0;
	82
	83	k = 0;
	84	while (chs_table[k].size > 0 && size > chs_table[k].size)
	85	k++;
	86
	87	if (chs_table[k].size > 0) {
	88	if (cyl)
	89	*cyl = chs_table[k].cyl;
	90	if (head)
	91	*head = chs_table[k].head;
	92	if (sec)
	93	*sec = chs_table[k].sec;
	94	found = 1;
	95	}
	96
	97	return found;
	98	}
	99
	100	/* These bytes are the signature for the CIS/IDI sector */
	101	static const uint8_t cis_numbers[] = {
	102	0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
	103	};
	104
	105	/* Read and check for a valid CIS sector */
	106	static int get_valid_cis_sector(struct mtd_info *mtd)
	107	{
	108	int ret, k, cis_sector;
	109	size_t retlen;
	110	loff_t offset;
9a05eded DW	111	uint8_t *sect_buf;
	112
	113	cis_sector = -1;
	114
	115	sect_buf = kmalloc(SECTOR_SIZE, GFP_KERNEL);
	116	if (!sect_buf)
	117	goto out;
51197abf CL	118
	119	/*
	120	* Look for CIS/IDI sector on the first GOOD block (give up after 4 bad
	121	* blocks). If the first good block doesn't contain CIS number the flash
	122	* is not SSFDC formatted
	123	*/
51197abf CL	124	for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) {
	125	if (!mtd->block_isbad(mtd, offset)) {
	126	ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen,
	127	sect_buf);
	128
	129	/* CIS pattern match on the sector buffer */
08d3ad6a	130	if (ret < 0 \|\| retlen != SECTOR_SIZE) {
51197abf CL	131	printk(KERN_WARNING
51197abf CL	132	"SSFDC_RO:can't read CIS/IDI sector\n");
08d3ad6a DW	133	} else if (!memcmp(sect_buf, cis_numbers,
08d3ad6a DW	134	sizeof(cis_numbers))) {
51197abf CL	135	/* Found */
	136	cis_sector = (int)(offset >> SECTOR_SHIFT);
	137	} else {
	138	DEBUG(MTD_DEBUG_LEVEL1,
	139	"SSFDC_RO: CIS/IDI sector not found"
	140	" on %s (mtd%d)\n", mtd->name,
	141	mtd->index);
	142	}
	143	break;
	144	}
	145	}
	146
9a05eded DW	147	kfree(sect_buf);
9a05eded DW	148	out:
51197abf CL	149	return cis_sector;
	150	}
	151
	152	/* Read physical sector (wrapper to MTD_READ) */
	153	static int read_physical_sector(struct mtd_info mtd, uint8_t sect_buf,
	154	int sect_no)
	155	{
	156	int ret;
	157	size_t retlen;
	158	loff_t offset = (loff_t)sect_no << SECTOR_SHIFT;
	159
	160	ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
	161	if (ret < 0 \|\| retlen != SECTOR_SIZE)
	162	return -1;
	163
	164	return 0;
	165	}
	166
	167	/* Read redundancy area (wrapper to MTD_READ_OOB */
	168	static int read_raw_oob(struct mtd_info mtd, loff_t offs, uint8_t buf)
	169	{
	170	struct mtd_oob_ops ops;
	171	int ret;
	172
	173	ops.mode = MTD_OOB_RAW;
	174	ops.ooboffs = 0;
7014568b	175	ops.ooblen = OOB_SIZE;
51197abf CL	176	ops.oobbuf = buf;
	177	ops.datbuf = NULL;
	178
	179	ret = mtd->read_oob(mtd, offs, &ops);
7014568b	180	if (ret < 0 \|\| ops.oobretlen != OOB_SIZE)
51197abf CL	181	return -1;
	182
	183	return 0;
	184	}
	185
	186	/* Parity calculator on a word of n bit size */
	187	static int get_parity(int number, int size)
	188	{
	189	int k;
	190	int parity;
	191
	192	parity = 1;
	193	for (k = 0; k < size; k++) {
	194	parity += (number >> k);
	195	parity &= 1;
	196	}
	197	return parity;
	198	}
	199
	200	/* Read and validate the logical block address field stored in the OOB */
	201	static int get_logical_address(uint8_t *oob_buf)
	202	{
	203	int block_address, parity;
	204	int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
	205	int j;
	206	int ok = 0;
	207
	208	/*
	209	* Look for the first valid logical address
	210	* Valid address has fixed pattern on most significant bits and
	211	* parity check
	212	*/
	213	for (j = 0; j < ARRAY_SIZE(offset); j++) {
	214	block_address = ((int)oob_buf[offset[j]] << 8) \|
	215	oob_buf[offset[j]+1];
	216
	217	/* Check for the signature bits in the address field (MSBits) */
	218	if ((block_address & ~0x7FF) == 0x1000) {
	219	parity = block_address & 0x01;
	220	block_address &= 0x7FF;
	221	block_address >>= 1;
	222
	223	if (get_parity(block_address, 10) != parity) {
	224	DEBUG(MTD_DEBUG_LEVEL0,
	225	"SSFDC_RO: logical address field%d"
	226	"parity error(0x%04X)\n", j+1,
	227	block_address);
	228	} else {
	229	ok = 1;
	230	break;
	231	}
	232	}
	233	}
	234
08d3ad6a	235	if (!ok)
51197abf CL	236	block_address = -2;
	237
	238	DEBUG(MTD_DEBUG_LEVEL3, "SSFDC_RO: get_logical_address() %d\n",
	239	block_address);
	240
	241	return block_address;
	242	}
	243
	244	/* Build the logic block map */
	245	static int build_logical_block_map(struct ssfdcr_record *ssfdc)
	246	{
	247	unsigned long offset;
	248	uint8_t oob_buf[OOB_SIZE];
	249	int ret, block_address, phys_block;
	250	struct mtd_info *mtd = ssfdc->mbd.mtd;
	251
	252	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: build_block_map() nblks=%d (%luK)\n",
08d3ad6a DW	253	ssfdc->map_len,
08d3ad6a DW	254	(unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024);
51197abf CL	255
	256	/* Scan every physical block, skip CIS block */
	257	for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len;
	258	phys_block++) {
	259	offset = (unsigned long)phys_block * ssfdc->erase_size;
	260	if (mtd->block_isbad(mtd, offset))
	261	continue; /* skip bad blocks */
	262
	263	ret = read_raw_oob(mtd, offset, oob_buf);
	264	if (ret < 0) {
	265	DEBUG(MTD_DEBUG_LEVEL0,
	266	"SSFDC_RO: mtd read_oob() failed at %lu\n",
	267	offset);
	268	return -1;
	269	}
	270	block_address = get_logical_address(oob_buf);
	271
	272	/* Skip invalid addresses */
	273	if (block_address >= 0 &&
	274	block_address < MAX_LOGIC_BLK_PER_ZONE) {
	275	int zone_index;
	276
	277	zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE;
	278	block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE;
	279	ssfdc->logic_block_map[block_address] =
	280	(unsigned short)phys_block;
	281
	282	DEBUG(MTD_DEBUG_LEVEL2,
	283	"SSFDC_RO: build_block_map() phys_block=%d,"
	284	"logic_block_addr=%d, zone=%d\n",
	285	phys_block, block_address, zone_index);
	286	}
	287	}
	288	return 0;
	289	}
	290
	291	static void ssfdcr_add_mtd(struct mtd_blktrans_ops tr, struct mtd_info mtd)
	292	{
	293	struct ssfdcr_record *ssfdc;
	294	int cis_sector;
	295
	296	/* Check for small page NAND flash */
69423d99 AH	297	if (mtd->type != MTD_NANDFLASH \|\| mtd->oobsize != OOB_SIZE \|\|
69423d99 AH	298	mtd->size > UINT_MAX)
51197abf CL	299	return;
	300
	301	/* Check for SSDFC format by reading CIS/IDI sector */
	302	cis_sector = get_valid_cis_sector(mtd);
	303	if (cis_sector == -1)
	304	return;
	305
	306	ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL);
	307	if (!ssfdc) {
	308	printk(KERN_WARNING
	309	"SSFDC_RO: out of memory for data structures\n");
	310	return;
	311	}
	312
	313	ssfdc->mbd.mtd = mtd;
	314	ssfdc->mbd.devnum = -1;
51197abf CL	315	ssfdc->mbd.tr = tr;
	316	ssfdc->mbd.readonly = 1;
	317
	318	ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT);
	319	ssfdc->erase_size = mtd->erasesize;
69423d99	320	ssfdc->map_len = (u32)mtd->size / mtd->erasesize;
51197abf CL	321
	322	DEBUG(MTD_DEBUG_LEVEL1,
	323	"SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n",
	324	ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len,
c8872b06	325	DIV_ROUND_UP(ssfdc->map_len, MAX_PHYS_BLK_PER_ZONE));
51197abf CL	326
	327	/* Set geometry */
	328	ssfdc->heads = 16;
	329	ssfdc->sectors = 32;
08d3ad6a	330	get_chs(mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors);
69423d99	331	ssfdc->cylinders = (unsigned short)(((u32)mtd->size >> SECTOR_SHIFT) /
51197abf CL	332	((long)ssfdc->sectors * (long)ssfdc->heads));
	333
	334	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n",
	335	ssfdc->cylinders, ssfdc->heads , ssfdc->sectors,
	336	(long)ssfdc->cylinders * (long)ssfdc->heads *
08d3ad6a	337	(long)ssfdc->sectors);
51197abf CL	338
	339	ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders *
	340	(long)ssfdc->sectors;
	341
	342	/* Allocate logical block map */
08d3ad6a DW	343	ssfdc->logic_block_map = kmalloc(sizeof(ssfdc->logic_block_map[0]) *
08d3ad6a DW	344	ssfdc->map_len, GFP_KERNEL);
51197abf CL	345	if (!ssfdc->logic_block_map) {
	346	printk(KERN_WARNING
	347	"SSFDC_RO: out of memory for data structures\n");
	348	goto out_err;
	349	}
	350	memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) *
	351	ssfdc->map_len);
	352
	353	/* Build logical block map */
	354	if (build_logical_block_map(ssfdc) < 0)
	355	goto out_err;
	356
	357	/* Register device + partitions */
	358	if (add_mtd_blktrans_dev(&ssfdc->mbd))
	359	goto out_err;
	360
	361	printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n",
	362	ssfdc->mbd.devnum + 'a', mtd->index, mtd->name);
	363	return;
	364
	365	out_err:
	366	kfree(ssfdc->logic_block_map);
	367	kfree(ssfdc);
	368	}
	369
	370	static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev)
	371	{
	372	struct ssfdcr_record ssfdc = (struct ssfdcr_record )dev;
	373
	374	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: remove_dev (i=%d)\n", dev->devnum);
	375
	376	del_mtd_blktrans_dev(dev);
	377	kfree(ssfdc->logic_block_map);
51197abf CL	378	}
	379
	380	static int ssfdcr_readsect(struct mtd_blktrans_dev *dev,
	381	unsigned long logic_sect_no, char *buf)
	382	{
	383	struct ssfdcr_record ssfdc = (struct ssfdcr_record )dev;
	384	int sectors_per_block, offset, block_address;
	385
	386	sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT;
	387	offset = (int)(logic_sect_no % sectors_per_block);
	388	block_address = (int)(logic_sect_no / sectors_per_block);
	389
	390	DEBUG(MTD_DEBUG_LEVEL3,
	391	"SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d,"
	392	" block_addr=%d\n", logic_sect_no, sectors_per_block, offset,
	393	block_address);
	394
	395	if (block_address >= ssfdc->map_len)
	396	BUG();
	397
	398	block_address = ssfdc->logic_block_map[block_address];
	399
	400	DEBUG(MTD_DEBUG_LEVEL3,
	401	"SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n",
	402	block_address);
	403
	404	if (block_address < 0xffff) {
	405	unsigned long sect_no;
	406
	407	sect_no = (unsigned long)block_address * sectors_per_block +
	408	offset;
	409
	410	DEBUG(MTD_DEBUG_LEVEL3,
	411	"SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n",
	412	sect_no);
	413
08d3ad6a	414	if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0)
51197abf CL	415	return -EIO;
	416	} else {
	417	memset(buf, 0xff, SECTOR_SIZE);
	418	}
	419
	420	return 0;
	421	}
	422
	423	static int ssfdcr_getgeo(struct mtd_blktrans_dev dev, struct hd_geometry geo)
	424	{
	425	struct ssfdcr_record ssfdc = (struct ssfdcr_record )dev;
	426
	427	DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n",
	428	ssfdc->cylinders, ssfdc->heads, ssfdc->sectors);
	429
	430	geo->heads = ssfdc->heads;
	431	geo->sectors = ssfdc->sectors;
	432	geo->cylinders = ssfdc->cylinders;
	433
	434	return 0;
	435	}
	436
	437	/****************************************************************************
	438	*
	439	* Module stuff
	440	*
	441	****************************************************************************/
	442
	443	static struct mtd_blktrans_ops ssfdcr_tr = {
	444	.name = "ssfdc",
	445	.major = SSFDCR_MAJOR,
	446	.part_bits = SSFDCR_PARTN_BITS,
76ab40e4	447	.blksize = SECTOR_SIZE,
51197abf CL	448	.getgeo = ssfdcr_getgeo,
	449	.readsect = ssfdcr_readsect,
	450	.add_mtd = ssfdcr_add_mtd,
	451	.remove_dev = ssfdcr_remove_dev,
	452	.owner = THIS_MODULE,
	453	};
	454
	455	static int __init init_ssfdcr(void)
	456	{
	457	printk(KERN_INFO "SSFDC read-only Flash Translation layer\n");
	458
	459	return register_mtd_blktrans(&ssfdcr_tr);
	460	}
	461
	462	static void __exit cleanup_ssfdcr(void)
	463	{
	464	deregister_mtd_blktrans(&ssfdcr_tr);
	465	}
	466
	467	module_init(init_ssfdcr);
	468	module_exit(cleanup_ssfdcr);
	469
	470	MODULE_LICENSE("GPL");
	471	MODULE_AUTHOR("Claudio Lanconelli <[email protected]>");
	472	MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card");