Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Common code to handle map devices which are simple RAM |
| 3 | * (C) 2000 Red Hat. GPL'd. |
| 4 | * $Id: map_ram.c,v 1.22 2005/01/05 18:05:12 dwmw2 Exp $ |
| 5 | */ |
| 6 | |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/types.h> |
| 9 | #include <linux/kernel.h> |
| 10 | #include <asm/io.h> |
| 11 | #include <asm/byteorder.h> |
| 12 | #include <linux/errno.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/mtd/mtd.h> |
| 16 | #include <linux/mtd/map.h> |
| 17 | #include <linux/mtd/compatmac.h> |
| 18 | |
| 19 | |
| 20 | static int mapram_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); |
| 21 | static int mapram_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *); |
| 22 | static int mapram_erase (struct mtd_info *, struct erase_info *); |
| 23 | static void mapram_nop (struct mtd_info *); |
| 24 | static struct mtd_info *map_ram_probe(struct map_info *map); |
| 25 | |
| 26 | |
| 27 | static struct mtd_chip_driver mapram_chipdrv = { |
| 28 | .probe = map_ram_probe, |
| 29 | .name = "map_ram", |
| 30 | .module = THIS_MODULE |
| 31 | }; |
| 32 | |
| 33 | static struct mtd_info *map_ram_probe(struct map_info *map) |
| 34 | { |
| 35 | struct mtd_info *mtd; |
| 36 | |
| 37 | /* Check the first byte is RAM */ |
| 38 | #if 0 |
| 39 | map_write8(map, 0x55, 0); |
| 40 | if (map_read8(map, 0) != 0x55) |
| 41 | return NULL; |
| 42 | |
| 43 | map_write8(map, 0xAA, 0); |
| 44 | if (map_read8(map, 0) != 0xAA) |
| 45 | return NULL; |
| 46 | |
| 47 | /* Check the last byte is RAM */ |
| 48 | map_write8(map, 0x55, map->size-1); |
| 49 | if (map_read8(map, map->size-1) != 0x55) |
| 50 | return NULL; |
| 51 | |
| 52 | map_write8(map, 0xAA, map->size-1); |
| 53 | if (map_read8(map, map->size-1) != 0xAA) |
| 54 | return NULL; |
| 55 | #endif |
| 56 | /* OK. It seems to be RAM. */ |
| 57 | |
| 58 | mtd = kmalloc(sizeof(*mtd), GFP_KERNEL); |
| 59 | if (!mtd) |
| 60 | return NULL; |
| 61 | |
| 62 | memset(mtd, 0, sizeof(*mtd)); |
| 63 | |
| 64 | map->fldrv = &mapram_chipdrv; |
| 65 | mtd->priv = map; |
| 66 | mtd->name = map->name; |
David Woodhouse | 21c8db9 | 2006-06-14 21:39:48 +0100 | [diff] [blame] | 67 | mtd->type = MTD_RAM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | mtd->size = map->size; |
| 69 | mtd->erase = mapram_erase; |
| 70 | mtd->read = mapram_read; |
| 71 | mtd->write = mapram_write; |
| 72 | mtd->sync = mapram_nop; |
Jörn Engel | a6c591e | 2006-04-13 18:54:34 +0200 | [diff] [blame] | 73 | mtd->flags = MTD_CAP_RAM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
| 75 | mtd->erasesize = PAGE_SIZE; |
| 76 | while(mtd->size & (mtd->erasesize - 1)) |
| 77 | mtd->erasesize >>= 1; |
| 78 | |
| 79 | __module_get(THIS_MODULE); |
| 80 | return mtd; |
| 81 | } |
| 82 | |
| 83 | |
| 84 | static int mapram_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) |
| 85 | { |
| 86 | struct map_info *map = mtd->priv; |
| 87 | |
| 88 | map_copy_from(map, buf, from, len); |
| 89 | *retlen = len; |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | static int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) |
| 94 | { |
| 95 | struct map_info *map = mtd->priv; |
| 96 | |
| 97 | map_copy_to(map, to, buf, len); |
| 98 | *retlen = len; |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr) |
| 103 | { |
| 104 | /* Yeah, it's inefficient. Who cares? It's faster than a _real_ |
| 105 | flash erase. */ |
| 106 | struct map_info *map = mtd->priv; |
| 107 | map_word allff; |
| 108 | unsigned long i; |
| 109 | |
| 110 | allff = map_word_ff(map); |
| 111 | |
| 112 | for (i=0; i<instr->len; i += map_bankwidth(map)) |
| 113 | map_write(map, allff, instr->addr + i); |
| 114 | |
| 115 | instr->state = MTD_ERASE_DONE; |
| 116 | |
| 117 | mtd_erase_callback(instr); |
| 118 | |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static void mapram_nop(struct mtd_info *mtd) |
| 123 | { |
| 124 | /* Nothing to see here */ |
| 125 | } |
| 126 | |
| 127 | static int __init map_ram_init(void) |
| 128 | { |
| 129 | register_mtd_chip_driver(&mapram_chipdrv); |
| 130 | return 0; |
| 131 | } |
| 132 | |
| 133 | static void __exit map_ram_exit(void) |
| 134 | { |
| 135 | unregister_mtd_chip_driver(&mapram_chipdrv); |
| 136 | } |
| 137 | |
| 138 | module_init(map_ram_init); |
| 139 | module_exit(map_ram_exit); |
| 140 | |
| 141 | MODULE_LICENSE("GPL"); |
| 142 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 143 | MODULE_DESCRIPTION("MTD chip driver for RAM chips"); |