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