sm_common.h

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/*
 * Copyright © 2009 - Maxim Levitsky
 * Common routines & support for SmartMedia/xD format
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/bitops.h>
#include <linux/mtd/mtd.h>

/* Full oob structure as written on the flash */
struct sm_oob {
    uint32_t reserved;
    uint8_t data_status;
    uint8_t block_status;
    uint8_t lba_copy1[2];
    uint8_t ecc2[3];
    uint8_t lba_copy2[2];
    uint8_t ecc1[3];
} __attribute__((packed));


/* one sector is always 512 bytes, but it can consist of two nand pages */
#define SM_SECTOR_SIZE      512

/* oob area is also 16 bytes, but might be from two pages */
#define SM_OOB_SIZE     16

/* This is maximum zone size, and all devices that have more that one zone
   have this size */
#define SM_MAX_ZONE_SIZE    1024

/* support for small page nand */
#define SM_SMALL_PAGE       256
#define SM_SMALL_OOB_SIZE   8


extern int sm_register_device(struct mtd_info *mtd, int smartmedia);


static inline int sm_sector_valid(struct sm_oob *oob)
{
    return hweight16(oob->data_status) >= 5;
}

static inline int sm_block_valid(struct sm_oob *oob)
{
    return hweight16(oob->block_status) >= 7;
}

static inline int sm_block_erased(struct sm_oob *oob)
{
    static const uint32_t erased_pattern[4] = {
        0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };

    /* First test for erased block */
    if (!memcmp(oob, erased_pattern, sizeof(*oob)))
        return 1;
    return 0;
}