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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | /* * Common code to handle map devices which are simple ROM * (C) 2000 Red Hat. GPL'd. */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <asm/io.h> #include <asm/byteorder.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/of.h> #include <linux/mtd/mtd.h> #include <linux/mtd/map.h> static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *); static void maprom_nop (struct mtd_info *); static struct mtd_info *map_rom_probe(struct map_info *map); static int maprom_erase (struct mtd_info *mtd, struct erase_info *info); static unsigned long maprom_unmapped_area(struct mtd_info *, unsigned long, unsigned long, unsigned long); static struct mtd_chip_driver maprom_chipdrv = { .probe = map_rom_probe, .name = "map_rom", .module = THIS_MODULE }; static unsigned int default_erasesize(struct map_info *map) { const __be32 *erase_size = NULL; erase_size = of_get_property(map->device_node, "erase-size", NULL); return !erase_size ? map->size : be32_to_cpu(*erase_size); } static struct mtd_info *map_rom_probe(struct map_info *map) { struct mtd_info *mtd; mtd = kzalloc(sizeof(*mtd), GFP_KERNEL); if (!mtd) return NULL; map->fldrv = &maprom_chipdrv; mtd->priv = map; mtd->name = map->name; mtd->type = MTD_ROM; mtd->size = map->size; mtd->_get_unmapped_area = maprom_unmapped_area; mtd->_read = maprom_read; mtd->_write = maprom_write; mtd->_sync = maprom_nop; mtd->_erase = maprom_erase; mtd->flags = MTD_CAP_ROM; mtd->erasesize = default_erasesize(map); mtd->writesize = 1; mtd->writebufsize = 1; __module_get(THIS_MODULE); return mtd; } /* * Allow NOMMU mmap() to directly map the device (if not NULL) * - return the address to which the offset maps * - return -ENOSYS to indicate refusal to do the mapping */ static unsigned long maprom_unmapped_area(struct mtd_info *mtd, unsigned long len, unsigned long offset, unsigned long flags) { struct map_info *map = mtd->priv; return (unsigned long) map->virt + offset; } static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { struct map_info *map = mtd->priv; map_copy_from(map, buf, from, len); *retlen = len; return 0; } static void maprom_nop(struct mtd_info *mtd) { /* Nothing to see here */ } static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { return -EROFS; } static int maprom_erase (struct mtd_info *mtd, struct erase_info *info) { /* We do our best 8) */ return -EROFS; } static int __init map_rom_init(void) { register_mtd_chip_driver(&maprom_chipdrv); return 0; } static void __exit map_rom_exit(void) { unregister_mtd_chip_driver(&maprom_chipdrv); } module_init(map_rom_init); module_exit(map_rom_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); MODULE_DESCRIPTION("MTD chip driver for ROM chips"); |