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 #include <linux/mtd/compatmac.h> 17 18 static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); 19 static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *); 20 static void maprom_nop (struct mtd_info *); 21 static struct mtd_info *map_rom_probe(struct map_info *map); 22 static int maprom_erase (struct mtd_info *mtd, struct erase_info *info); 23 static unsigned long maprom_unmapped_area(struct mtd_info *, unsigned long, 24 unsigned long, unsigned long); 25 26 static struct mtd_chip_driver maprom_chipdrv = { 27 .probe = map_rom_probe, 28 .name = "map_rom", 29 .module = THIS_MODULE 30 }; 31 32 static struct mtd_info *map_rom_probe(struct map_info *map) 33 { 34 struct mtd_info *mtd; 35 36 mtd = kzalloc(sizeof(*mtd), GFP_KERNEL); 37 if (!mtd) 38 return NULL; 39 40 map->fldrv = &maprom_chipdrv; 41 mtd->priv = map; 42 mtd->name = map->name; 43 mtd->type = MTD_ROM; 44 mtd->size = map->size; 45 mtd->get_unmapped_area = maprom_unmapped_area; 46 mtd->read = maprom_read; 47 mtd->write = maprom_write; 48 mtd->sync = maprom_nop; 49 mtd->erase = maprom_erase; 50 mtd->flags = MTD_CAP_ROM; 51 mtd->erasesize = map->size; 52 mtd->writesize = 1; 53 54 __module_get(THIS_MODULE); 55 return mtd; 56 } 57 58 59 /* 60 * Allow NOMMU mmap() to directly map the device (if not NULL) 61 * - return the address to which the offset maps 62 * - return -ENOSYS to indicate refusal to do the mapping 63 */ 64 static unsigned long maprom_unmapped_area(struct mtd_info *mtd, 65 unsigned long len, 66 unsigned long offset, 67 unsigned long flags) 68 { 69 struct map_info *map = mtd->priv; 70 return (unsigned long) map->virt + offset; 71 } 72 73 static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) 74 { 75 struct map_info *map = mtd->priv; 76 77 map_copy_from(map, buf, from, len); 78 *retlen = len; 79 return 0; 80 } 81 82 static void maprom_nop(struct mtd_info *mtd) 83 { 84 /* Nothing to see here */ 85 } 86 87 static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) 88 { 89 printk(KERN_NOTICE "maprom_write called\n"); 90 return -EIO; 91 } 92 93 static int maprom_erase (struct mtd_info *mtd, struct erase_info *info) 94 { 95 /* We do our best 8) */ 96 return -EROFS; 97 } 98 99 static int __init map_rom_init(void) 100 { 101 register_mtd_chip_driver(&maprom_chipdrv); 102 return 0; 103 } 104 105 static void __exit map_rom_exit(void) 106 { 107 unregister_mtd_chip_driver(&maprom_chipdrv); 108 } 109 110 module_init(map_rom_init); 111 module_exit(map_rom_exit); 112 113 MODULE_LICENSE("GPL"); 114 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 115 MODULE_DESCRIPTION("MTD chip driver for ROM chips"); 116