/*

   * Simple read-only (writable only for RAM) mtdblock driver

   *
   * Copyright © 2001-2010 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/init.h>
  #include <linux/slab.h>
  #include <linux/mtd/mtd.h>
  #include <linux/mtd/blktrans.h>

  #include <linux/module.h>

  
  static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
  			      unsigned long block, char *buf)
  {
  	size_t retlen;

  	if (mtd_read(dev->mtd, (block * 512), 512, &retlen, buf))

  		return 1;
  	return 0;
  }
  
  static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
  			      unsigned long block, char *buf)
  {
  	size_t retlen;

  	if (mtd_write(dev->mtd, (block * 512), 512, &retlen, buf))

  		return 1;
  	return 0;
  }
  
  static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
  {

  	struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);

  
  	if (!dev)
  		return;

  	dev->mtd = mtd;
  	dev->devnum = mtd->index;

  	dev->size = mtd->size >> 9;
  	dev->tr = tr;

  	dev->readonly = 1;

  	if (add_mtd_blktrans_dev(dev))
  		kfree(dev);

  }
  
  static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
  {
  	del_mtd_blktrans_dev(dev);

  }
  
  static struct mtd_blktrans_ops mtdblock_tr = {
  	.name		= "mtdblock",
  	.major		= 31,
  	.part_bits	= 0,

  	.blksize 	= 512,

  	.readsect	= mtdblock_readsect,
  	.writesect	= mtdblock_writesect,
  	.add_mtd	= mtdblock_add_mtd,
  	.remove_dev	= mtdblock_remove_dev,
  	.owner		= THIS_MODULE,
  };
  
  static int __init mtdblock_init(void)
  {
  	return register_mtd_blktrans(&mtdblock_tr);
  }
  
  static void __exit mtdblock_exit(void)
  {
  	deregister_mtd_blktrans(&mtdblock_tr);
  }
  
  module_init(mtdblock_init);
  module_exit(mtdblock_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
  MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");