xref: /openbmc/linux/drivers/mtd/chips/map_rom.c (revision 643d1f7f)
1 /*
2  * Common code to handle map devices which are simple ROM
3  * (C) 2000 Red Hat. GPL'd.
4  * $Id: map_rom.c,v 1.23 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 static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
20 static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
21 static void maprom_nop (struct mtd_info *);
22 static struct mtd_info *map_rom_probe(struct map_info *map);
23 
24 static struct mtd_chip_driver maprom_chipdrv = {
25 	.probe	= map_rom_probe,
26 	.name	= "map_rom",
27 	.module	= THIS_MODULE
28 };
29 
30 static struct mtd_info *map_rom_probe(struct map_info *map)
31 {
32 	struct mtd_info *mtd;
33 
34 	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
35 	if (!mtd)
36 		return NULL;
37 
38 	map->fldrv = &maprom_chipdrv;
39 	mtd->priv = map;
40 	mtd->name = map->name;
41 	mtd->type = MTD_ROM;
42 	mtd->size = map->size;
43 	mtd->read = maprom_read;
44 	mtd->write = maprom_write;
45 	mtd->sync = maprom_nop;
46 	mtd->flags = MTD_CAP_ROM;
47 	mtd->erasesize = map->size;
48 	mtd->writesize = 1;
49 
50 	__module_get(THIS_MODULE);
51 	return mtd;
52 }
53 
54 
55 static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
56 {
57 	struct map_info *map = mtd->priv;
58 
59 	map_copy_from(map, buf, from, len);
60 	*retlen = len;
61 	return 0;
62 }
63 
64 static void maprom_nop(struct mtd_info *mtd)
65 {
66 	/* Nothing to see here */
67 }
68 
69 static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
70 {
71 	printk(KERN_NOTICE "maprom_write called\n");
72 	return -EIO;
73 }
74 
75 static int __init map_rom_init(void)
76 {
77 	register_mtd_chip_driver(&maprom_chipdrv);
78 	return 0;
79 }
80 
81 static void __exit map_rom_exit(void)
82 {
83 	unregister_mtd_chip_driver(&maprom_chipdrv);
84 }
85 
86 module_init(map_rom_init);
87 module_exit(map_rom_exit);
88 
89 MODULE_LICENSE("GPL");
90 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
91 MODULE_DESCRIPTION("MTD chip driver for ROM chips");
92