mtdblock_ro.c 1.8 KB

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  1. /*
  2. * $Id: mtdblock_ro.c,v 1.1.1.1 2007/06/12 07:27:09 eyryu Exp $
  3. *
  4. * (C) 2003 David Woodhouse <dwmw2@infradead.org>
  5. *
  6. * Simple read-only (writable only for RAM) mtdblock driver
  7. */
  8. #include <linux/init.h>
  9. #include <linux/slab.h>
  10. #include <linux/mtd/mtd.h>
  11. #include <linux/mtd/blktrans.h>
  12. static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
  13. unsigned long block, char *buf)
  14. {
  15. size_t retlen;
  16. if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
  17. return 1;
  18. return 0;
  19. }
  20. static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
  21. unsigned long block, char *buf)
  22. {
  23. size_t retlen;
  24. if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
  25. return 1;
  26. return 0;
  27. }
  28. static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
  29. {
  30. struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  31. if (!dev)
  32. return;
  33. dev->mtd = mtd;
  34. dev->devnum = mtd->index;
  35. dev->size = mtd->size >> 9;
  36. dev->tr = tr;
  37. dev->readonly = 1;
  38. add_mtd_blktrans_dev(dev);
  39. }
  40. static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
  41. {
  42. del_mtd_blktrans_dev(dev);
  43. kfree(dev);
  44. }
  45. static struct mtd_blktrans_ops mtdblock_tr = {
  46. .name = "mtdblock",
  47. .major = 31,
  48. .part_bits = 0,
  49. .blksize = 512,
  50. .readsect = mtdblock_readsect,
  51. .writesect = mtdblock_writesect,
  52. .add_mtd = mtdblock_add_mtd,
  53. .remove_dev = mtdblock_remove_dev,
  54. .owner = THIS_MODULE,
  55. };
  56. static int __init mtdblock_init(void)
  57. {
  58. return register_mtd_blktrans(&mtdblock_tr);
  59. }
  60. static void __exit mtdblock_exit(void)
  61. {
  62. deregister_mtd_blktrans(&mtdblock_tr);
  63. }
  64. module_init(mtdblock_init);
  65. module_exit(mtdblock_exit);
  66. MODULE_LICENSE("GPL");
  67. MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
  68. MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");