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/of.h>
  15#include <linux/mtd/mtd.h>
  16#include <linux/mtd/map.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 int maprom_point (struct mtd_info *mtd, loff_t from, size_t len,
  24                         size_t *retlen, void **virt, resource_size_t *phys);
  25static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
  26
  27
  28static struct mtd_chip_driver maprom_chipdrv = {
  29        .probe  = map_rom_probe,
  30        .name   = "map_rom",
  31        .module = THIS_MODULE
  32};
  33
  34static unsigned int default_erasesize(struct map_info *map)
  35{
  36        const __be32 *erase_size = NULL;
  37
  38        erase_size = of_get_property(map->device_node, "erase-size", NULL);
  39
  40        return !erase_size ? map->size : be32_to_cpu(*erase_size);
  41}
  42
  43static struct mtd_info *map_rom_probe(struct map_info *map)
  44{
  45        struct mtd_info *mtd;
  46
  47        mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
  48        if (!mtd)
  49                return NULL;
  50
  51        map->fldrv = &maprom_chipdrv;
  52        mtd->priv = map;
  53        mtd->name = map->name;
  54        mtd->type = MTD_ROM;
  55        mtd->size = map->size;
  56        mtd->_point = maprom_point;
  57        mtd->_unpoint = maprom_unpoint;
  58        mtd->_read = maprom_read;
  59        mtd->_write = maprom_write;
  60        mtd->_sync = maprom_nop;
  61        mtd->_erase = maprom_erase;
  62        mtd->flags = MTD_CAP_ROM;
  63        mtd->erasesize = default_erasesize(map);
  64        mtd->writesize = 1;
  65        mtd->writebufsize = 1;
  66
  67        __module_get(THIS_MODULE);
  68        return mtd;
  69}
  70
  71
  72static int maprom_point(struct mtd_info *mtd, loff_t from, size_t len,
  73                        size_t *retlen, void **virt, resource_size_t *phys)
  74{
  75        struct map_info *map = mtd->priv;
  76
  77        if (!map->virt)
  78                return -EINVAL;
  79        *virt = map->virt + from;
  80        if (phys)
  81                *phys = map->phys + from;
  82        *retlen = len;
  83        return 0;
  84}
  85
  86static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  87{
  88        return 0;
  89}
  90
  91static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
  92{
  93        struct map_info *map = mtd->priv;
  94
  95        map_copy_from(map, buf, from, len);
  96        *retlen = len;
  97        return 0;
  98}
  99
 100static void maprom_nop(struct mtd_info *mtd)
 101{
 102        /* Nothing to see here */
 103}
 104
 105static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
 106{
 107        return -EROFS;
 108}
 109
 110static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
 111{
 112        /* We do our best 8) */
 113        return -EROFS;
 114}
 115
 116static int __init map_rom_init(void)
 117{
 118        register_mtd_chip_driver(&maprom_chipdrv);
 119        return 0;
 120}
 121
 122static void __exit map_rom_exit(void)
 123{
 124        unregister_mtd_chip_driver(&maprom_chipdrv);
 125}
 126
 127module_init(map_rom_init);
 128module_exit(map_rom_exit);
 129
 130MODULE_LICENSE("GPL");
 131MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 132MODULE_DESCRIPTION("MTD chip driver for ROM chips");
 133