// SPDX-License-Identifier: GPL-2.0
/*
 * drivers/mtd/nand/raw/nand_util.c
 *
 * Copyright (C) 2006 by Weiss-Electronic GmbH.
 * All rights reserved.
 *
 * @author:     Guido Classen <clagix@gmail.com>
 * @descr:      NAND Flash support
 * @references: borrowed heavily from Linux mtd-utils code:
 *              flash_eraseall.c by Arcom Control System Ltd
 *              nandwrite.c by Steven J. Hill (sjhill@realitydiluted.com)
 *                             and Thomas Gleixner (tglx@linutronix.de)
 *
 * Copyright (C) 2008 Nokia Corporation: drop_ffs() function by
 * Artem Bityutskiy <dedekind1@gmail.com> from mtd-utils
 *
 * Copyright 2010 Freescale Semiconductor
 */

#include <common.h>
#include <command.h>
#include <watchdog.h>
#include <malloc.h>
#include <memalign.h>
#include <div64.h>

#include <linux/errno.h>
#include <linux/mtd/mtd.h>
#include <nand.h>
#include <jffs2/jffs2.h>

typedef struct erase_info       erase_info_t;
typedef struct mtd_info         mtd_info_t;

/* support only for native endian JFFS2 */
#define cpu_to_je16(x) (x)
#define cpu_to_je32(x) (x)

/**
 * nand_erase_opts: - erase NAND flash with support for various options
 *                    (jffs2 formatting)
 *
 * @param mtd           nand mtd instance to erase
 * @param opts          options,  @see struct nand_erase_options
 * @return              0 in case of success
 *
 * This code is ported from flash_eraseall.c from Linux mtd utils by
 * Arcom Control System Ltd.
 */
int nand_erase_opts(struct mtd_info *mtd,
                    const nand_erase_options_t *opts)
{
        struct jffs2_unknown_node cleanmarker;
        erase_info_t erase;
        unsigned long erase_length, erased_length; /* in blocks */
        int result;
        int percent_complete = -1;
        const char *mtd_device = mtd->name;
        struct mtd_oob_ops oob_opts;
        struct nand_chip *chip = mtd_to_nand(mtd);

        if ((opts->offset & (mtd->erasesize - 1)) != 0) {
                printf("Attempt to erase non block-aligned data\n");
                return -1;
        }

        memset(&erase, 0, sizeof(erase));
        memset(&oob_opts, 0, sizeof(oob_opts));

        erase.mtd = mtd;
        erase.len = mtd->erasesize;
        erase.addr = opts->offset;
        erase_length = lldiv(opts->length + mtd->erasesize - 1,
                             mtd->erasesize);

        cleanmarker.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
        cleanmarker.nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER);
        cleanmarker.totlen = cpu_to_je32(8);

        /* scrub option allows to erase badblock. To prevent internal
         * check from erase() method, set block check method to dummy
         * and disable bad block table while erasing.
         */
        if (opts->scrub) {
                erase.scrub = opts->scrub;
                /*
                 * We don't need the bad block table anymore...
                 * after scrub, there are no bad blocks left!
                 */
                if (chip->bbt) {
                        kfree(chip->bbt);
                }
                chip->bbt = NULL;
                chip->options &= ~NAND_BBT_SCANNED;
        }

        for (erased_length = 0;
             erased_length < erase_length;
             erase.addr += mtd->erasesize) {

                WATCHDOG_RESET();

                if (opts->lim && (erase.addr >= (opts->offset + opts->lim))) {
                        puts("Size of erase exceeds limit\n");
                        return -EFBIG;
                }
                if (!opts->scrub) {
                        int ret = mtd_block_isbad(mtd, erase.addr);
                        if (ret > 0) {
                                if (!opts->quiet)
                                        printf("\rSkipping bad block at  "
                                               "0x%08llx                 "
                                               "                         \n",
                                               erase.addr);

                                if (!opts->spread)
                                        erased_length++;

                                continue;

                        } else if (ret < 0) {
                                printf("\n%s: MTD get bad block failed: %d\n",
                                       mtd_device,
                                       ret);
                                return -1;
                        }
                }

                erased_length++;

                result = mtd_erase(mtd, &erase);
                if (result != 0) {
                        printf("\n%s: MTD Erase failure: %d\n",
                               mtd_device, result);
                        continue;
                }

                /* format for JFFS2 ? */
                if (opts->jffs2 && chip->ecc.layout->oobavail >= 8) {
                        struct mtd_oob_ops ops;
                        ops.ooblen = 8;
                        ops.datbuf = NULL;
                        ops.oobbuf = (uint8_t *)&cleanmarker;
                        ops.ooboffs = 0;
                        ops.mode = MTD_OPS_AUTO_OOB;

                        result = mtd_write_oob(mtd, erase.addr, &ops);
                        if (result != 0) {
                                printf("\n%s: MTD writeoob failure: %d\n",
                                       mtd_device, result);
                                continue;
                        }
                }

                if (!opts->quiet) {
                        unsigned long long n = erased_length * 100ULL;
                        int percent;

                        do_div(n, erase_length);
                        percent = (int)n;

                        /* output progress message only at whole percent
                         * steps to reduce the number of messages printed
                         * on (slow) serial consoles
                         */
                        if (percent != percent_complete) {
                                percent_complete = percent;

                                printf("\rErasing at 0x%llx -- %3d%% complete.",
                                       erase.addr, percent);

                                if (opts->jffs2 && result == 0)
                                        printf(" Cleanmarker written at 0x%llx.",
                                               erase.addr);
                        }
                }
        }
        if (!opts->quiet)
                printf("\n");

        return 0;
}

#ifdef CONFIG_CMD_NAND_LOCK_UNLOCK

#define NAND_CMD_LOCK_TIGHT     0x2c
#define NAND_CMD_LOCK_STATUS    0x7a
 
/******************************************************************************
 * Support for locking / unlocking operations of some NAND devices
 *****************************************************************************/

/**
 * nand_lock: Set all pages of NAND flash chip to the LOCK or LOCK-TIGHT
 *            state
 *
 * @param mtd           nand mtd instance
 * @param tight         bring device in lock tight mode
 *
 * @return              0 on success, -1 in case of error
 *
 * The lock / lock-tight command only applies to the whole chip. To get some
 * parts of the chip lock and others unlocked use the following sequence:
 *
 * - Lock all pages of the chip using nand_lock(mtd, 0) (or the lockpre pin)
 * - Call nand_unlock() once for each consecutive area to be unlocked
 * - If desired: Bring the chip to the lock-tight state using nand_lock(mtd, 1)
 *
 *   If the device is in lock-tight state software can't change the
 *   current active lock/unlock state of all pages. nand_lock() / nand_unlock()
 *   calls will fail. It is only posible to leave lock-tight state by
 *   an hardware signal (low pulse on _WP pin) or by power down.
 */
int nand_lock(struct mtd_info *mtd, int tight)
{
        int ret = 0;
        int status;
        struct nand_chip *chip = mtd_to_nand(mtd);

        /* select the NAND device */
        chip->select_chip(mtd, 0);

        /* check the Lock Tight Status */
        chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, 0);
        if (chip->read_byte(mtd) & NAND_LOCK_STATUS_TIGHT) {
                printf("nand_lock: Device is locked tight!\n");
                ret = -1;
                goto out;
        }

        chip->cmdfunc(mtd,
                      (tight ? NAND_CMD_LOCK_TIGHT : NAND_CMD_LOCK),
                      -1, -1);

        /* call wait ready function */
        status = chip->waitfunc(mtd, chip);

        /* see if device thinks it succeeded */
        if (status & 0x01) {
                ret = -1;
        }

 out:
        /* de-select the NAND device */
        chip->select_chip(mtd, -1);
        return ret;
}

/**
 * nand_get_lock_status: - query current lock state from one page of NAND
 *                         flash
 *
 * @param mtd           nand mtd instance
 * @param offset        page address to query (must be page-aligned!)
 *
 * @return              -1 in case of error
 *                      >0 lock status:
 *                        bitfield with the following combinations:
 *                        NAND_LOCK_STATUS_TIGHT: page in tight state
 *                        NAND_LOCK_STATUS_UNLOCK: page unlocked
 *
 */
int nand_get_lock_status(struct mtd_info *mtd, loff_t offset)
{
        int ret = 0;
        int chipnr;
        int page;
        struct nand_chip *chip = mtd_to_nand(mtd);

        /* select the NAND device */
        chipnr = (int)(offset >> chip->chip_shift);
        chip->select_chip(mtd, chipnr);


        if ((offset & (mtd->writesize - 1)) != 0) {
                printf("nand_get_lock_status: "
                        "Start address must be beginning of "
                        "nand page!\n");
                ret = -1;
                goto out;
        }

        /* check the Lock Status */
        page = (int)(offset >> chip->page_shift);
        chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, page & chip->pagemask);

        ret = chip->read_byte(mtd) & (NAND_LOCK_STATUS_TIGHT
                                          | NAND_LOCK_STATUS_UNLOCK);

 out:
        /* de-select the NAND device */
        chip->select_chip(mtd, -1);
        return ret;
}

/**
 * nand_unlock: - Unlock area of NAND pages
 *                only one consecutive area can be unlocked at one time!
 *
 * @param mtd           nand mtd instance
 * @param start         start byte address
 * @param length        number of bytes to unlock (must be a multiple of
 *                      page size mtd->writesize)
 * @param allexcept     if set, unlock everything not selected
 *
 * @return              0 on success, -1 in case of error
 */
int nand_unlock(struct mtd_info *mtd, loff_t start, size_t length,
        int allexcept)
{
        int ret = 0;
        int chipnr;
        int status;
        int page;
        struct nand_chip *chip = mtd_to_nand(mtd);

        debug("nand_unlock%s: start: %08llx, length: %zd!\n",
                allexcept ? " (allexcept)" : "", start, length);

        /* select the NAND device */
        chipnr = (int)(start >> chip->chip_shift);
        chip->select_chip(mtd, chipnr);

        /* check the WP bit */
        chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
        if (!(chip->read_byte(mtd) & NAND_STATUS_WP)) {
                printf("nand_unlock: Device is write protected!\n");
                ret = -1;
                goto out;
        }

        /* check the Lock Tight Status */
        page = (int)(start >> chip->page_shift);
        chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, page & chip->pagemask);
        if (chip->read_byte(mtd) & NAND_LOCK_STATUS_TIGHT) {
                printf("nand_unlock: Device is locked tight!\n");
                ret = -1;
                goto out;
        }

        if ((start & (mtd->erasesize - 1)) != 0) {
                printf("nand_unlock: Start address must be beginning of "
                        "nand block!\n");
                ret = -1;
                goto out;
        }

        if (length == 0 || (length & (mtd->erasesize - 1)) != 0) {
                printf("nand_unlock: Length must be a multiple of nand block "
                        "size %08x!\n", mtd->erasesize);
                ret = -1;
                goto out;
        }

        /*
         * Set length so that the last address is set to the
         * starting address of the last block
         */
        length -= mtd->erasesize;

        /* submit address of first page to unlock */
        chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);

        /* submit ADDRESS of LAST page to unlock */
        page += (int)(length >> chip->page_shift);

        /*
         * Page addresses for unlocking are supposed to be block-aligned.
         * At least some NAND chips use the low bit to indicate that the
         * page range should be inverted.
         */
        if (allexcept)
                page |= 1;

        chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1, page & chip->pagemask);

        /* call wait ready function */
        status = chip->waitfunc(mtd, chip);
        /* see if device thinks it succeeded */
        if (status & 0x01) {
                /* there was an error */
                ret = -1;
                goto out;
        }

 out:
        /* de-select the NAND device */
        chip->select_chip(mtd, -1);
        return ret;
}
#endif

/**
 * check_skip_len
 *
 * Check if there are any bad blocks, and whether length including bad
 * blocks fits into device
 *
 * @param mtd nand mtd instance
 * @param offset offset in flash
 * @param length image length
 * @param used length of flash needed for the requested length
 * @return 0 if the image fits and there are no bad blocks
 *         1 if the image fits, but there are bad blocks
 *        -1 if the image does not fit
 */
static int check_skip_len(struct mtd_info *mtd, loff_t offset, size_t length,
                          size_t *used)
{
        size_t len_excl_bad = 0;
        int ret = 0;

        while (len_excl_bad < length) {
                size_t block_len, block_off;
                loff_t block_start;

                if (offset >= mtd->size)
                        return -1;

                block_start = offset & ~(loff_t)(mtd->erasesize - 1);
                block_off = offset & (mtd->erasesize - 1);
                block_len = mtd->erasesize - block_off;

                if (!nand_block_isbad(mtd, block_start))
                        len_excl_bad += block_len;
                else
                        ret = 1;

                offset += block_len;
                *used += block_len;
        }

        /* If the length is not a multiple of block_len, adjust. */
        if (len_excl_bad > length)
                *used -= (len_excl_bad - length);

        return ret;
}

#ifdef CONFIG_CMD_NAND_TRIMFFS
static size_t drop_ffs(const struct mtd_info *mtd, const u_char *buf,
                        const size_t *len)
{
        size_t l = *len;
        ssize_t i;

        for (i = l - 1; i >= 0; i--)
                if (buf[i] != 0xFF)
                        break;

        /* The resulting length must be aligned to the minimum flash I/O size */
        l = i + 1;
        l = (l + mtd->writesize - 1) / mtd->writesize;
        l *=  mtd->writesize;

        /*
         * since the input length may be unaligned, prevent access past the end
         * of the buffer
         */
        return min(l, *len);
}
#endif

/**
 * nand_verify_page_oob:
 *
 * Verify a page of NAND flash, including the OOB.
 * Reads page of NAND and verifies the contents and OOB against the
 * values in ops.
 *
 * @param mtd           nand mtd instance
 * @param ops           MTD operations, including data to verify
 * @param ofs           offset in flash
 * @return              0 in case of success
 */
int nand_verify_page_oob(struct mtd_info *mtd, struct mtd_oob_ops *ops,
                         loff_t ofs)
{
        int rval;
        struct mtd_oob_ops vops;
        size_t verlen = mtd->writesize + mtd->oobsize;

        memcpy(&vops, ops, sizeof(vops));

        vops.datbuf = memalign(ARCH_DMA_MINALIGN, verlen);

        if (!vops.datbuf)
                return -ENOMEM;

        vops.oobbuf = vops.datbuf + mtd->writesize;

        rval = mtd_read_oob(mtd, ofs, &vops);
        if (!rval)
                rval = memcmp(ops->datbuf, vops.datbuf, vops.len);
        if (!rval)
                rval = memcmp(ops->oobbuf, vops.oobbuf, vops.ooblen);

        free(vops.datbuf);

        return rval ? -EIO : 0;
}

/**
 * nand_verify:
 *
 * Verify a region of NAND flash.
 * Reads NAND in page-sized chunks and verifies the contents against
 * the contents of a buffer.  The offset into the NAND must be
 * page-aligned, and the function doesn't handle skipping bad blocks.
 *
 * @param mtd           nand mtd instance
 * @param ofs           offset in flash
 * @param len           buffer length
 * @param buf           buffer to read from
 * @return              0 in case of success
 */
int nand_verify(struct mtd_info *mtd, loff_t ofs, size_t len, u_char *buf)
{
        int rval = 0;
        size_t verofs;
        size_t verlen = mtd->writesize;
        uint8_t *verbuf = memalign(ARCH_DMA_MINALIGN, verlen);

        if (!verbuf)
                return -ENOMEM;

        /* Read the NAND back in page-size groups to limit malloc size */
        for (verofs = ofs; verofs < ofs + len;
             verofs += verlen, buf += verlen) {
                verlen = min(mtd->writesize, (uint32_t)(ofs + len - verofs));
                rval = nand_read(mtd, verofs, &verlen, verbuf);
                if (!rval || (rval == -EUCLEAN))
                        rval = memcmp(buf, verbuf, verlen);

                if (rval)
                        break;
        }

        free(verbuf);

        return rval ? -EIO : 0;
}



/**
 * nand_write_skip_bad:
 *
 * Write image to NAND flash.
 * Blocks that are marked bad are skipped and the is written to the next
 * block instead as long as the image is short enough to fit even after
 * skipping the bad blocks.  Due to bad blocks we may not be able to
 * perform the requested write.  In the case where the write would
 * extend beyond the end of the NAND device, both length and actual (if
 * not NULL) are set to 0.  In the case where the write would extend
 * beyond the limit we are passed, length is set to 0 and actual is set
 * to the required length.
 *
 * @param mtd           nand mtd instance
 * @param offset        offset in flash
 * @param length        buffer length
 * @param actual        set to size required to write length worth of
 *                      buffer or 0 on error, if not NULL
 * @param lim           maximum size that actual may be in order to not
 *                      exceed the buffer
 * @param buffer        buffer to read from
 * @param flags         flags modifying the behaviour of the write to NAND
 * @return              0 in case of success
 */
int nand_write_skip_bad(struct mtd_info *mtd, loff_t offset, size_t *length,
                        size_t *actual, loff_t lim, u_char *buffer, int flags)
{
        int rval = 0, blocksize;
        size_t left_to_write = *length;
        size_t used_for_write = 0;
        u_char *p_buffer = buffer;
        int need_skip;

        if (actual)
                *actual = 0;

        blocksize = mtd->erasesize;

        /*
         * nand_write() handles unaligned, partial page writes.
         *
         * We allow length to be unaligned, for convenience in
         * using the $filesize variable.
         *
         * However, starting at an unaligned offset makes the
         * semantics of bad block skipping ambiguous (really,
         * you should only start a block skipping access at a
         * partition boundary).  So don't try to handle that.
         */
        if ((offset & (mtd->writesize - 1)) != 0) {
                printf("Attempt to write non page-aligned data\n");
                *length = 0;
                return -EINVAL;
        }

        need_skip = check_skip_len(mtd, offset, *length, &used_for_write);

        if (actual)
                *actual = used_for_write;

        if (need_skip < 0) {
                printf("Attempt to write outside the flash area\n");
                *length = 0;
                return -EINVAL;
        }

        if (used_for_write > lim) {
                puts("Size of write exceeds partition or device limit\n");
                *length = 0;
                return -EFBIG;
        }

        if (!need_skip && !(flags & WITH_DROP_FFS)) {
                rval = nand_write(mtd, offset, length, buffer);

                if ((flags & WITH_WR_VERIFY) && !rval)
                        rval = nand_verify(mtd, offset, *length, buffer);

                if (rval == 0)
                        return 0;

                *length = 0;
                printf("NAND write to offset %llx failed %d\n",
                        offset, rval);
                return rval;
        }

        while (left_to_write > 0) {
                loff_t block_start = offset & ~(loff_t)(mtd->erasesize - 1);
                size_t block_offset = offset & (mtd->erasesize - 1);
                size_t write_size, truncated_write_size;

                WATCHDOG_RESET();

                if (nand_block_isbad(mtd, block_start)) {
                        printf("Skip bad block 0x%08llx\n", block_start);
                        offset += mtd->erasesize - block_offset;
                        continue;
                }

                if (left_to_write < (blocksize - block_offset))
                        write_size = left_to_write;
                else
                        write_size = blocksize - block_offset;

                truncated_write_size = write_size;
#ifdef CONFIG_CMD_NAND_TRIMFFS
                if (flags & WITH_DROP_FFS)
                        truncated_write_size = drop_ffs(mtd, p_buffer,
                                        &write_size);
#endif

                rval = nand_write(mtd, offset, &truncated_write_size,
                                p_buffer);

                if ((flags & WITH_WR_VERIFY) && !rval)
                        rval = nand_verify(mtd, offset,
                                truncated_write_size, p_buffer);

                offset += write_size;
                p_buffer += write_size;

                if (rval != 0) {
                        printf("NAND write to offset %llx failed %d\n",
                                offset, rval);
                        *length -= left_to_write;
                        return rval;
                }

                left_to_write -= write_size;
        }

        return 0;
}

/**
 * nand_read_skip_bad:
 *
 * Read image from NAND flash.
 * Blocks that are marked bad are skipped and the next block is read
 * instead as long as the image is short enough to fit even after
 * skipping the bad blocks.  Due to bad blocks we may not be able to
 * perform the requested read.  In the case where the read would extend
 * beyond the end of the NAND device, both length and actual (if not
 * NULL) are set to 0.  In the case where the read would extend beyond
 * the limit we are passed, length is set to 0 and actual is set to the
 * required length.
 *
 * @param mtd nand mtd instance
 * @param offset offset in flash
 * @param length buffer length, on return holds number of read bytes
 * @param actual set to size required to read length worth of buffer or 0
 * on error, if not NULL
 * @param lim maximum size that actual may be in order to not exceed the
 * buffer
 * @param buffer buffer to write to
 * @return 0 in case of success
 */
int nand_read_skip_bad(struct mtd_info *mtd, loff_t offset, size_t *length,
                       size_t *actual, loff_t lim, u_char *buffer)
{
        int rval;
        size_t left_to_read = *length;
        size_t used_for_read = 0;
        u_char *p_buffer = buffer;
        int need_skip;

        if ((offset & (mtd->writesize - 1)) != 0) {
                printf("Attempt to read non page-aligned data\n");
                *length = 0;
                if (actual)
                        *actual = 0;
                return -EINVAL;
        }

        need_skip = check_skip_len(mtd, offset, *length, &used_for_read);

        if (actual)
                *actual = used_for_read;

        if (need_skip < 0) {
                printf("Attempt to read outside the flash area\n");
                *length = 0;
                return -EINVAL;
        }

        if (used_for_read > lim) {
                puts("Size of read exceeds partition or device limit\n");
                *length = 0;
                return -EFBIG;
        }

        if (!need_skip) {
                rval = nand_read(mtd, offset, length, buffer);
                if (!rval || rval == -EUCLEAN)
                        return 0;

                *length = 0;
                printf("NAND read from offset %llx failed %d\n",
                        offset, rval);
                return rval;
        }

        while (left_to_read > 0) {
                size_t block_offset = offset & (mtd->erasesize - 1);
                size_t read_length;

                WATCHDOG_RESET();

                if (nand_block_isbad(mtd, offset & ~(mtd->erasesize - 1))) {
                        printf("Skipping bad block 0x%08llx\n",
                                offset & ~(mtd->erasesize - 1));
                        offset += mtd->erasesize - block_offset;
                        continue;
                }

                if (left_to_read < (mtd->erasesize - block_offset))
                        read_length = left_to_read;
                else
                        read_length = mtd->erasesize - block_offset;

                rval = nand_read(mtd, offset, &read_length, p_buffer);
                if (rval && rval != -EUCLEAN) {
                        printf("NAND read from offset %llx failed %d\n",
                                offset, rval);
                        *length -= left_to_read;
                        return rval;
                }

                left_to_read -= read_length;
                offset       += read_length;
                p_buffer     += read_length;
        }

        return 0;
}

#ifdef CONFIG_CMD_NAND_TORTURE

/**
 * check_pattern:
 *
 * Check if buffer contains only a certain byte pattern.
 *
 * @param buf buffer to check
 * @param patt the pattern to check
 * @param size buffer size in bytes
 * @return 1 if there are only patt bytes in buf
 *         0 if something else was found
 */
static int check_pattern(const u_char *buf, u_char patt, int size)
{
        int i;

        for (i = 0; i < size; i++)
                if (buf[i] != patt)
                        return 0;
        return 1;
}

/**
 * nand_torture:
 *
 * Torture a block of NAND flash.
 * This is useful to determine if a block that caused a write error is still
 * good or should be marked as bad.
 *
 * @param mtd nand mtd instance
 * @param offset offset in flash
 * @return 0 if the block is still good
 */
int nand_torture(struct mtd_info *mtd, loff_t offset)
{
        u_char patterns[] = {0xa5, 0x5a, 0x00};
        struct erase_info instr = {
                .mtd = mtd,
                .addr = offset,
                .len = mtd->erasesize,
        };
        size_t retlen;
        int err, ret = -1, i, patt_count;
        u_char *buf;

        if ((offset & (mtd->erasesize - 1)) != 0) {
                puts("Attempt to torture a block at a non block-aligned offset\n");
                return -EINVAL;
        }

        if (offset + mtd->erasesize > mtd->size) {
                puts("Attempt to torture a block outside the flash area\n");
                return -EINVAL;
        }

        patt_count = ARRAY_SIZE(patterns);

        buf = malloc_cache_aligned(mtd->erasesize);
        if (buf == NULL) {
                puts("Out of memory for erase block buffer\n");
                return -ENOMEM;
        }

        for (i = 0; i < patt_count; i++) {
                err = mtd_erase(mtd, &instr);
                if (err) {
                        printf("%s: erase() failed for block at 0x%llx: %d\n",
                                mtd->name, instr.addr, err);
                        goto out;
                }

                /* Make sure the block contains only 0xff bytes */
                err = mtd_read(mtd, offset, mtd->erasesize, &retlen, buf);
                if ((err && err != -EUCLEAN) || retlen != mtd->erasesize) {
                        printf("%s: read() failed for block at 0x%llx: %d\n",
                                mtd->name, instr.addr, err);
                        goto out;
                }

                err = check_pattern(buf, 0xff, mtd->erasesize);
                if (!err) {
                        printf("Erased block at 0x%llx, but a non-0xff byte was found\n",
                                offset);
                        ret = -EIO;
                        goto out;
                }

                /* Write a pattern and check it */
                memset(buf, patterns[i], mtd->erasesize);
                err = mtd_write(mtd, offset, mtd->erasesize, &retlen, buf);
                if (err || retlen != mtd->erasesize) {
                        printf("%s: write() failed for block at 0x%llx: %d\n",
                                mtd->name, instr.addr, err);
                        goto out;
                }

                err = mtd_read(mtd, offset, mtd->erasesize, &retlen, buf);
                if ((err && err != -EUCLEAN) || retlen != mtd->erasesize) {
                        printf("%s: read() failed for block at 0x%llx: %d\n",
                                mtd->name, instr.addr, err);
                        goto out;
                }

                err = check_pattern(buf, patterns[i], mtd->erasesize);
                if (!err) {
                        printf("Pattern 0x%.2x checking failed for block at "
                                        "0x%llx\n", patterns[i], offset);
                        ret = -EIO;
                        goto out;
                }
        }

        ret = 0;

out:
        free(buf);
        return ret;
}

#endif