/* * 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");