linux-imx

/*

 * Simple MTD partitioning layer

 *

 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>

 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>

 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 */

​

#include <linux/module.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/list.h>

#include <linux/kmod.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/partitions.h>

#include <linux/err.h>

#include <linux/of.h>

​

#include "mtdcore.h"

​

/* Our partition linked list */

static LIST_HEAD(mtd_partitions);

static DEFINE_MUTEX(mtd_partitions_mutex);

​

/**

 * struct mtd_part - our partition node structure

 *

 * @mtd: struct holding partition details

 * @parent: parent mtd - flash device or another partition

 * @offset: partition offset relative to the *flash device*

 */

struct mtd_part {

    struct mtd_info mtd;

    struct mtd_info *parent;

    uint64_t offset;

    struct list_head list;

};

​

/*

 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve

 * the pointer to that structure.

 */

static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)

{

    return container_of(mtd, struct mtd_part, mtd);

}

​

static u64 part_absolute_offset(struct mtd_info *mtd)

{

    struct mtd_part *part = mtd_to_part(mtd);

​

    if (!mtd_is_partition(mtd))

        return 0;

​

    return part_absolute_offset(part->parent) + part->offset;

}

​

/*

 * MTD methods which simply translate the effective address and pass through

 * to the _real_ device.

 */

​

static int part_read(struct mtd_info *mtd, loff_t from, size_t len,

        size_t *retlen, u_char *buf)

{

    struct mtd_part *part = mtd_to_part(mtd);

    struct mtd_ecc_stats stats;

    int res;

​

    stats = part->parent->ecc_stats;

    res = part->parent->_read(part->parent, from + part->offset, len,

                  retlen, buf);

    if (unlikely(mtd_is_eccerr(res)))

        mtd->ecc_stats.failed +=

            part->parent->ecc_stats.failed - stats.failed;

    else