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linux/drivers/mtd/ssfdc.c
Vitaly Wool 7014568bad [MTD] [NAND] remove len/ooblen confusion. 
As was discussed between Ricard Wanderlöf, David Woodhouse, Artem 
Bityutskiy and me, the current API for reading/writing OOB is confusing. 

The thing that introduces confusion is the need to specify ops.len 
together with ops.ooblen for reads/writes that concern only OOB not data 
area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to 
specify the length of the data read, and when ops.datbuf == NULL, it 
serves to specify the full OOB read length.

The patch inlined below is the slightly updated version of the previous 
patch serving the same purpose, but with the new Artem's comments taken 
into account.

Artem, BTW, thanks a lot for your valuable input!

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-11-28 22:39:03 +00:00

474 lines
12 KiB
C
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/*
* Linux driver for SSFDC Flash Translation Layer (Read only)
* (c) 2005 Eptar srl
* Author: Claudio Lanconelli <lanconelli.claudio@eptar.com>
*
* 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)
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.blksize = SECTOR_SIZE;
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 = 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,
(ssfdc->map_len + MAX_PHYS_BLK_PER_ZONE - 1) /
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)((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);
kfree(ssfdc);
}
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,
.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 <lanconelli.claudio@eptar.com>");
MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card");
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