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mtd: common module for smartmedia/xD support

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This small module implements few helpers that are usefull
for nand drivers for SmartMedia/xD card readers.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Maxim Levitsky
2010-02-22 20:39:39 +02:00
committed by David Woodhouse
parent e0b58d0a70
commit 9fc51a37a8
4 changed files with 178 additions and 0 deletions
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107
drivers/mtd/nand/sm_common.c Normal file
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/*
* Copyright © 2009 - Maxim Levitsky
* Common routines & support for xD format
*
* 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/mtd/nand.h>
#include "sm_common.h"
static struct nand_ecclayout nand_oob_sm = {
.eccbytes = 6,
.eccpos = {8, 9, 10, 13, 14, 15},
.oobfree = {
{.offset = 0 , .length = 4}, /* reserved */
{.offset = 6 , .length = 2}, /* LBA1 */
{.offset = 11, .length = 2} /* LBA2 */
}
};
/* NOTE: This layout is is not compatabable with SmartMedia, */
/* because the 256 byte devices have page depenent oob layout */
/* However it does preserve the bad block markers */
/* If you use smftl, it will bypass this and work correctly */
/* If you not, then you break SmartMedia compliance anyway */
static struct nand_ecclayout nand_oob_sm_small = {
.eccbytes = 3,
.eccpos = {0, 1, 2},
.oobfree = {
{.offset = 3 , .length = 2}, /* reserved */
{.offset = 6 , .length = 2}, /* LBA1 */
}
};
static int sm_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_oob_ops ops;
struct sm_oob oob;
int ret, error = 0;
memset(&oob, -1, SM_OOB_SIZE);
oob.block_status = 0x0F;
/* As long as this function is called on erase block boundaries
it will work correctly for 256 byte nand */
ops.mode = MTD_OOB_PLACE;
ops.ooboffs = 0;
ops.ooblen = mtd->oobsize;
ops.oobbuf = (void *)&oob;
ops.datbuf = NULL;
ret = mtd->write_oob(mtd, ofs, &ops);
if (ret < 0 || ops.oobretlen != SM_OOB_SIZE) {
printk(KERN_NOTICE
"sm_common: can't mark sector at %i as bad\n",
(int)ofs);
error = -EIO;
} else
mtd->ecc_stats.badblocks++;
return error;
}
int sm_register_device(struct mtd_info *mtd)
{
struct nand_chip *chip = (struct nand_chip *)mtd->priv;
int ret;
chip->options |= NAND_SKIP_BBTSCAN | NAND_SMARTMEDIA;
/* Scan for card properties */
ret = nand_scan_ident(mtd, 1);
if (ret)
return ret;
/* Bad block marker postion */
chip->badblockpos = 0x05;
chip->badblockbits = 7;
chip->block_markbad = sm_block_markbad;
/* ECC layout */
if (mtd->writesize == SM_SECTOR_SIZE)
chip->ecc.layout = &nand_oob_sm;
else if (mtd->writesize == SM_SMALL_PAGE)
chip->ecc.layout = &nand_oob_sm_small;
else
return -ENODEV;
ret = nand_scan_tail(mtd);
if (ret)
return ret;
return add_mtd_device(mtd);
}
EXPORT_SYMBOL_GPL(sm_register_device);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
MODULE_DESCRIPTION("Common SmartMedia/xD functions");