1 /* 2 * Common code to handle map devices which are simple ROM 3 * (C) 2000 Red Hat. GPL'd. 4 */ 5 6 #include <linux/module.h> 7 #include <linux/types.h> 8 #include <linux/kernel.h> 9 #include <asm/io.h> 10 #include <asm/byteorder.h> 11 #include <linux/errno.h> 12 #include <linux/slab.h> 13 #include <linux/init.h> 14 #include <linux/mtd/mtd.h> 15 #include <linux/mtd/map.h> 16 17 static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); 18 static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *); 19 static void maprom_nop (struct mtd_info *); 20 static struct mtd_info *map_rom_probe(struct map_info *map); 21 static int maprom_erase (struct mtd_info *mtd, struct erase_info *info); 22 static unsigned long maprom_unmapped_area(struct mtd_info *, unsigned long, 23 unsigned long, unsigned long); 24 25 static struct mtd_chip_driver maprom_chipdrv = { 26 .probe = map_rom_probe, 27 .name = "map_rom", 28 .module = THIS_MODULE 29 }; 30 31 static struct mtd_info *map_rom_probe(struct map_info *map) 32 { 33 struct mtd_info *mtd; 34 35 mtd = kzalloc(sizeof(*mtd), GFP_KERNEL); 36 if (!mtd) 37 return NULL; 38 39 map->fldrv = &maprom_chipdrv; 40 mtd->priv = map; 41 mtd->name = map->name; 42 mtd->type = MTD_ROM; 43 mtd->size = map->size; 44 mtd->get_unmapped_area = maprom_unmapped_area; 45 mtd->read = maprom_read; 46 mtd->write = maprom_write; 47 mtd->sync = maprom_nop; 48 mtd->erase = maprom_erase; 49 mtd->flags = MTD_CAP_ROM; 50 mtd->erasesize = map->size; 51 mtd->writesize = 1; 52 53 __module_get(THIS_MODULE); 54 return mtd; 55 } 56 57 58 /* 59 * Allow NOMMU mmap() to directly map the device (if not NULL) 60 * - return the address to which the offset maps 61 * - return -ENOSYS to indicate refusal to do the mapping 62 */ 63 static unsigned long maprom_unmapped_area(struct mtd_info *mtd, 64 unsigned long len, 65 unsigned long offset, 66 unsigned long flags) 67 { 68 struct map_info *map = mtd->priv; 69 return (unsigned long) map->virt + offset; 70 } 71 72 static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) 73 { 74 struct map_info *map = mtd->priv; 75 76 map_copy_from(map, buf, from, len); 77 *retlen = len; 78 return 0; 79 } 80 81 static void maprom_nop(struct mtd_info *mtd) 82 { 83 /* Nothing to see here */ 84 } 85 86 static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) 87 { 88 printk(KERN_NOTICE "maprom_write called\n"); 89 return -EIO; 90 } 91 92 static int maprom_erase (struct mtd_info *mtd, struct erase_info *info) 93 { 94 /* We do our best 8) */ 95 return -EROFS; 96 } 97 98 static int __init map_rom_init(void) 99 { 100 register_mtd_chip_driver(&maprom_chipdrv); 101 return 0; 102 } 103 104 static void __exit map_rom_exit(void) 105 { 106 unregister_mtd_chip_driver(&maprom_chipdrv); 107 } 108 109 module_init(map_rom_init); 110 module_exit(map_rom_exit); 111 112 MODULE_LICENSE("GPL"); 113 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 114 MODULE_DESCRIPTION("MTD chip driver for ROM chips"); 115