drivers/mtd/chips/map_rom.c

   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 = kmalloc(sizeof(*mtd), GFP_KERNEL);
  35         if (!mtd)
  36                 return NULL;
  37
  38         memset(mtd, 0, sizeof(*mtd));
  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->read = maprom_read;
  46         mtd->write = maprom_write;
  47         mtd->sync = maprom_nop;
  48         mtd->flags = MTD_CAP_ROM;
  49         mtd->erasesize = 131072;
  50         while(mtd->size & (mtd->erasesize - 1))
  51                 mtd->erasesize >>= 1;
  52
  53         __module_get(THIS_MODULE);
  54         return mtd;
  55 }
  56
  57
  58 static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
  59 {
  60         struct map_info *map = mtd->priv;
  61
  62         map_copy_from(map, buf, from, len);
  63         *retlen = len;
  64         return 0;
  65 }
  66
  67 static void maprom_nop(struct mtd_info *mtd)
  68 {
  69         /* Nothing to see here */
  70 }
  71
  72 static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
  73 {
  74         printk(KERN_NOTICE "maprom_write called\n");
  75         return -EIO;
  76 }
  77
  78 static int __init map_rom_init(void)
  79 {
  80         register_mtd_chip_driver(&maprom_chipdrv);
  81         return 0;
  82 }
  83
  84 static void __exit map_rom_exit(void)
  85 {
  86         unregister_mtd_chip_driver(&maprom_chipdrv);
  87 }
  88
  89 module_init(map_rom_init);
  90 module_exit(map_rom_exit);
  91
  92 MODULE_LICENSE("GPL");
  93 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
  94 MODULE_DESCRIPTION("MTD chip driver for ROM chips");