LXR linux/drivers/mtd/nand/sm

   1/*
   2 * Copyright © 2009 - Maxim Levitsky
   3 * Common routines & support for SmartMedia/xD format
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 */
   9#include <linux/bitops.h>
  10#include <linux/mtd/mtd.h>
  11
  12/* Full oob structure as written on the flash */
  13struct sm_oob {
  14        uint32_t reserved;
  15        uint8_t data_status;
  16        uint8_t block_status;
  17        uint8_t lba_copy1[2];
  18        uint8_t ecc2[3];
  19        uint8_t lba_copy2[2];
  20        uint8_t ecc1[3];
  21} __attribute__((packed));
  22
  23
  24/* one sector is always 512 bytes, but it can consist of two nand pages */
  25#define SM_SECTOR_SIZE          512
  26
  27/* oob area is also 16 bytes, but might be from two pages */
  28#define SM_OOB_SIZE             16
  29
  30/* This is maximum zone size, and all devices that have more that one zone
  31   have this size */
  32#define SM_MAX_ZONE_SIZE        1024
  33
  34/* support for small page nand */
  35#define SM_SMALL_PAGE           256
  36#define SM_SMALL_OOB_SIZE       8
  37
  38
  39extern int sm_register_device(struct mtd_info *mtd, int smartmedia);
  40
  41
  42static inline int sm_sector_valid(struct sm_oob *oob)
  43{
  44        return hweight16(oob->data_status) >= 5;
  45}
  46
  47static inline int sm_block_valid(struct sm_oob *oob)
  48{
  49        return hweight16(oob->block_status) >= 7;
  50}
  51
  52static inline int sm_block_erased(struct sm_oob *oob)
  53{
  54        static const uint32_t erased_pattern[4] = {
  55                0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
  56
  57        /* First test for erased block */
  58        if (!memcmp(oob, erased_pattern, sizeof(*oob)))
  59                return 1;
  60        return 0;
  61}
  62