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
  17static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
  18static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
  19static void maprom_nop (struct mtd_info *);
  20static struct mtd_info *map_rom_probe(struct map_info *map);
  21static int maprom_erase (struct mtd_info *mtd, struct erase_info *info);
  22static unsigned long maprom_unmapped_area(struct mtd_info *, unsigned long,
  23                                          unsigned long, unsigned long);
  24
  25static struct mtd_chip_driver maprom_chipdrv = {
  26        .probe  = map_rom_probe,
  27        .name   = "map_rom",
  28        .module = THIS_MODULE
  29};
  30
  31static struct mtd_info *map_rom_probe(struct map_info *map)
  32{
  33        struct mtd_info *mtd;
  34
  35        mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
  36        if (!mtd)
  37                return NULL;
  38
  39        map->fldrv = &maprom_chipdrv;
  40        mtd->priv = map;
  41        mtd->name = map->name;
  42        mtd->type = MTD_ROM;
  43        mtd->size = map->size;
  44        mtd->_get_unmapped_area = maprom_unmapped_area;
  45        mtd->_read = maprom_read;
  46        mtd->_write = maprom_write;
  47        mtd->_sync = maprom_nop;
  48        mtd->_erase = maprom_erase;
  49        mtd->flags = MTD_CAP_ROM;
  50        mtd->erasesize = map->size;
  51        mtd->writesize = 1;
  52
  53        __module_get(THIS_MODULE);
  54        return mtd;
  55}
  56
  57
  58/*
  59 * Allow NOMMU mmap() to directly map the device (if not NULL)
  60 * - return the address to which the offset maps
  61 * - return -ENOSYS to indicate refusal to do the mapping
  62 */
  63static unsigned long maprom_unmapped_area(struct mtd_info *mtd,
  64                                          unsigned long len,
  65                                          unsigned long offset,
  66                                          unsigned long flags)
  67{
  68        struct map_info *map = mtd->priv;
  69        return (unsigned long) map->virt + offset;
  70}
  71
  72static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
  73{
  74        struct map_info *map = mtd->priv;
  75
  76        map_copy_from(map, buf, from, len);
  77        *retlen = len;
  78        return 0;
  79}
  80
  81static void maprom_nop(struct mtd_info *mtd)
  82{
  83        /* Nothing to see here */
  84}
  85
  86static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
  87{
  88        return -EROFS;
  89}
  90
  91static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
  92{
  93        /* We do our best 8) */
  94        return -EROFS;
  95}
  96
  97static int __init map_rom_init(void)
  98{
  99        register_mtd_chip_driver(&maprom_chipdrv);
 100        return 0;
 101}
 102
 103static void __exit map_rom_exit(void)
 104{
 105        unregister_mtd_chip_driver(&maprom_chipdrv);
 106}
 107
 108module_init(map_rom_init);
 109module_exit(map_rom_exit);
 110
 111MODULE_LICENSE("GPL");
 112MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 113MODULE_DESCRIPTION("MTD chip driver for ROM chips");
 114