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/of.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/mtd/map.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 int maprom_point (struct mtd_info *mtd, loff_t from, size_t len,
24 size_t *retlen, void **virt, resource_size_t *phys);
25 static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
26
27
28 static struct mtd_chip_driver maprom_chipdrv = {
29 .probe = map_rom_probe,
30 .name = "map_rom",
31 .module = THIS_MODULE
32 };
33
default_erasesize(struct map_info * map)34 static unsigned int default_erasesize(struct map_info *map)
35 {
36 const __be32 *erase_size = NULL;
37
38 erase_size = of_get_property(map->device_node, "erase-size", NULL);
39
40 return !erase_size ? map->size : be32_to_cpu(*erase_size);
41 }
42
map_rom_probe(struct map_info * map)43 static struct mtd_info *map_rom_probe(struct map_info *map)
44 {
45 struct mtd_info *mtd;
46
47 mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
48 if (!mtd)
49 return NULL;
50
51 map->fldrv = &maprom_chipdrv;
52 mtd->priv = map;
53 mtd->name = map->name;
54 mtd->type = MTD_ROM;
55 mtd->size = map->size;
56 mtd->_point = maprom_point;
57 mtd->_unpoint = maprom_unpoint;
58 mtd->_read = maprom_read;
59 mtd->_write = maprom_write;
60 mtd->_sync = maprom_nop;
61 mtd->_erase = maprom_erase;
62 mtd->flags = MTD_CAP_ROM;
63 mtd->erasesize = default_erasesize(map);
64 mtd->writesize = 1;
65 mtd->writebufsize = 1;
66
67 __module_get(THIS_MODULE);
68 return mtd;
69 }
70
71
maprom_point(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,void ** virt,resource_size_t * phys)72 static int maprom_point(struct mtd_info *mtd, loff_t from, size_t len,
73 size_t *retlen, void **virt, resource_size_t *phys)
74 {
75 struct map_info *map = mtd->priv;
76
77 if (!map->virt)
78 return -EINVAL;
79 *virt = map->virt + from;
80 if (phys)
81 *phys = map->phys + from;
82 *retlen = len;
83 return 0;
84 }
85
maprom_unpoint(struct mtd_info * mtd,loff_t from,size_t len)86 static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
87 {
88 return 0;
89 }
90
maprom_read(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)91 static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
92 {
93 struct map_info *map = mtd->priv;
94
95 map_copy_from(map, buf, from, len);
96 *retlen = len;
97 return 0;
98 }
99
maprom_nop(struct mtd_info * mtd)100 static void maprom_nop(struct mtd_info *mtd)
101 {
102 /* Nothing to see here */
103 }
104
maprom_write(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)105 static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
106 {
107 return -EROFS;
108 }
109
maprom_erase(struct mtd_info * mtd,struct erase_info * info)110 static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
111 {
112 /* We do our best 8) */
113 return -EROFS;
114 }
115
map_rom_init(void)116 static int __init map_rom_init(void)
117 {
118 register_mtd_chip_driver(&maprom_chipdrv);
119 return 0;
120 }
121
map_rom_exit(void)122 static void __exit map_rom_exit(void)
123 {
124 unregister_mtd_chip_driver(&maprom_chipdrv);
125 }
126
127 module_init(map_rom_init);
128 module_exit(map_rom_exit);
129
130 MODULE_LICENSE("GPL");
131 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
132 MODULE_DESCRIPTION("MTD chip driver for ROM chips");
133
