1/* 2 * $Id: mtdblock_ro.c,v 1.1.1.1 2007/08/03 18:52:43 Exp $ 3 * 4 * (C) 2003 David Woodhouse <dwmw2@infradead.org> 5 * 6 * Simple read-only (writable only for RAM) mtdblock driver 7 */ 8 9#include <linux/init.h> 10#include <linux/slab.h> 11#include <linux/mtd/mtd.h> 12#include <linux/mtd/blktrans.h> 13 14static int mtdblock_readsect(struct mtd_blktrans_dev *dev, 15 unsigned long block, char *buf) 16{ 17 size_t retlen; 18 19 if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf)) 20 return 1; 21 return 0; 22} 23 24static int mtdblock_writesect(struct mtd_blktrans_dev *dev, 25 unsigned long block, char *buf) 26{ 27 size_t retlen; 28 29 if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf)) 30 return 1; 31 return 0; 32} 33 34static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) 35{ 36 struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL); 37 38 if (!dev) 39 return; 40 41 dev->mtd = mtd; 42 dev->devnum = mtd->index; 43 44 dev->size = mtd->size >> 9; 45 dev->tr = tr; 46 dev->readonly = 1; 47 48 add_mtd_blktrans_dev(dev); 49} 50 51static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev) 52{ 53 del_mtd_blktrans_dev(dev); 54 kfree(dev); 55} 56 57static struct mtd_blktrans_ops mtdblock_tr = { 58 .name = "mtdblock", 59 .major = 31, 60 .part_bits = 0, 61 .blksize = 512, 62 .readsect = mtdblock_readsect, 63 .writesect = mtdblock_writesect, 64 .add_mtd = mtdblock_add_mtd, 65 .remove_dev = mtdblock_remove_dev, 66 .owner = THIS_MODULE, 67}; 68 69static int __init mtdblock_init(void) 70{ 71 return register_mtd_blktrans(&mtdblock_tr); 72} 73 74static void __exit mtdblock_exit(void) 75{ 76 deregister_mtd_blktrans(&mtdblock_tr); 77} 78 79module_init(mtdblock_init); 80module_exit(mtdblock_exit); 81 82MODULE_LICENSE("GPL"); 83MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 84MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices"); 85