LXR linux/drivers/mtd/mtdblock

   1/*
   2 * (C) 2003 David Woodhouse <dwmw2@infradead.org>
   3 *
   4 * Simple read-only (writable only for RAM) mtdblock driver
   5 */
   6
   7#include <linux/init.h>
   8#include <linux/slab.h>
   9#include <linux/mtd/mtd.h>
  10#include <linux/mtd/blktrans.h>
  11
  12static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
  13                              unsigned long block, char *buf)
  14{
  15        size_t retlen;
  16
  17        if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
  18                return 1;
  19        return 0;
  20}
  21
  22static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
  23                              unsigned long block, char *buf)
  24{
  25        size_t retlen;
  26
  27        if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
  28                return 1;
  29        return 0;
  30}
  31
  32static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
  33{
  34        struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  35
  36        if (!dev)
  37                return;
  38
  39        dev->mtd = mtd;
  40        dev->devnum = mtd->index;
  41
  42        dev->size = mtd->size >> 9;
  43        dev->tr = tr;
  44        dev->readonly = 1;
  45
  46        add_mtd_blktrans_dev(dev);
  47}
  48
  49static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
  50{
  51        del_mtd_blktrans_dev(dev);
  52        kfree(dev);
  53}
  54
  55static struct mtd_blktrans_ops mtdblock_tr = {
  56        .name           = "mtdblock",
  57        .major          = 31,
  58        .part_bits      = 0,
  59        .blksize        = 512,
  60        .readsect       = mtdblock_readsect,
  61        .writesect      = mtdblock_writesect,
  62        .add_mtd        = mtdblock_add_mtd,
  63        .remove_dev     = mtdblock_remove_dev,
  64        .owner          = THIS_MODULE,
  65};
  66
  67static int __init mtdblock_init(void)
  68{
  69        return register_mtd_blktrans(&mtdblock_tr);
  70}
  71
  72static void __exit mtdblock_exit(void)
  73{
  74        deregister_mtd_blktrans(&mtdblock_tr);
  75}
  76
  77module_init(mtdblock_init);
  78module_exit(mtdblock_exit);
  79
  80MODULE_LICENSE("GPL");
  81MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
  82MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");
  83