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