LXR linux/drivers/mtd/chips/map

   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
  18static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
  19static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
  20static void maprom_nop (struct mtd_info *);
  21static struct mtd_info *map_rom_probe(struct map_info *map);
  22static int maprom_erase (struct mtd_info *mtd, struct erase_info *info);
  23static unsigned long maprom_unmapped_area(struct mtd_info *, unsigned long,
  24                                          unsigned long, unsigned long);
  25
  26static struct mtd_chip_driver maprom_chipdrv = {
  27        .probe  = map_rom_probe,
  28        .name   = "map_rom",
  29        .module = THIS_MODULE
  30};
  31
  32static struct mtd_info *map_rom_probe(struct map_info *map)
  33{
  34        struct mtd_info *mtd;
  35
  36        mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
  37        if (!mtd)
  38                return NULL;
  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->get_unmapped_area = maprom_unmapped_area;
  46        mtd->read = maprom_read;
  47        mtd->write = maprom_write;
  48        mtd->sync = maprom_nop;
  49        mtd->erase = maprom_erase;
  50        mtd->flags = MTD_CAP_ROM;
  51        mtd->erasesize = map->size;
  52        mtd->writesize = 1;
  53
  54        __module_get(THIS_MODULE);
  55        return mtd;
  56}
  57
  58
  59/*
  60 * Allow NOMMU mmap() to directly map the device (if not NULL)
  61 * - return the address to which the offset maps
  62 * - return -ENOSYS to indicate refusal to do the mapping
  63 */
  64static unsigned long maprom_unmapped_area(struct mtd_info *mtd,
  65                                          unsigned long len,
  66                                          unsigned long offset,
  67                                          unsigned long flags)
  68{
  69        struct map_info *map = mtd->priv;
  70        return (unsigned long) map->virt + offset;
  71}
  72
  73static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
  74{
  75        struct map_info *map = mtd->priv;
  76
  77        map_copy_from(map, buf, from, len);
  78        *retlen = len;
  79        return 0;
  80}
  81
  82static void maprom_nop(struct mtd_info *mtd)
  83{
  84        /* Nothing to see here */
  85}
  86
  87static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
  88{
  89        printk(KERN_NOTICE "maprom_write called\n");
  90        return -EIO;
  91}
  92
  93static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
  94{
  95        /* We do our best 8) */
  96        return -EROFS;
  97}
  98
  99static int __init map_rom_init(void)
 100{
 101        register_mtd_chip_driver(&maprom_chipdrv);
 102        return 0;
 103}
 104
 105static void __exit map_rom_exit(void)
 106{
 107        unregister_mtd_chip_driver(&maprom_chipdrv);
 108}
 109
 110module_init(map_rom_init);
 111module_exit(map_rom_exit);
 112
 113MODULE_LICENSE("GPL");
 114MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 115MODULE_DESCRIPTION("MTD chip driver for ROM chips");
 116