/*
 * drivers/mtd/nand/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
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 * Copyright 2010 Freescale Semiconductor
 * The portions of this file whose copyright is held by Freescale and which
 * are not considered a derived work of GPL v2-only code may be distributed
 * and/or modified under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 */

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

#include <asm/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)

/*****************************************************************************/
static int nand_block_bad_scrub(struct mtd_info *mtd, loff_t ofs, int getchip)
{
        return 0;
}

/**
 * nand_erase_opts: - erase NAND flash with support for various options
 *                    (jffs2 formating)
 *
 * @param meminfo       NAND device 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(nand_info_t *meminfo, const nand_erase_options_t *opts)
{
        struct jffs2_unknown_node cleanmarker;
        erase_info_t erase;
        unsigned long erase_length, erased_length; /* in blocks */
        int bbtest = 1;
        int result;
        int percent_complete = -1;
        int (*nand_block_bad_old)(struct mtd_info *, loff_t, int) = NULL;
        const char *mtd_device = meminfo->name;
        struct mtd_oob_ops oob_opts;
        struct nand_chip *chip = meminfo->priv;

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

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

        erase.mtd = meminfo;
        erase.len  = meminfo->erasesize;
        erase.addr = opts->offset;
        erase_length = lldiv(opts->length + meminfo->erasesize - 1,
                             meminfo->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) {
                struct nand_chip *priv_nand = meminfo->priv;

                nand_block_bad_old = priv_nand->block_bad;
                priv_nand->block_bad = nand_block_bad_scrub;
                /* we don't need the bad block table anymore...
                 * after scrub, there are no bad blocks left!
                 */
                if (priv_nand->bbt) {
                        kfree(priv_nand->bbt);
                }
                priv_nand->bbt = NULL;
        }

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

                WATCHDOG_RESET ();

                if (!opts->scrub && bbtest) {
                        int ret = meminfo->block_isbad(meminfo, 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 = meminfo->erase(meminfo, &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) {
                        chip->ops.ooblen = 8;
                        chip->ops.datbuf = NULL;
                        chip->ops.oobbuf = (uint8_t *)&cleanmarker;
                        chip->ops.ooboffs = 0;
                        chip->ops.mode = MTD_OOB_AUTO;

                        result = meminfo->write_oob(meminfo,
                                                    erase.addr,
                                                    &chip->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");

        if (nand_block_bad_old) {
                struct nand_chip *priv_nand = meminfo->priv;

                priv_nand->block_bad = nand_block_bad_old;
                priv_nand->scan_bbt(meminfo);
        }

        return 0;
}

#ifdef CONFIG_CMD_NAND_LOCK_UNLOCK

/******************************************************************************
 * Support for locking / unlocking operations of some NAND devices
 *****************************************************************************/

#define NAND_CMD_LOCK           0x2a
#define NAND_CMD_LOCK_TIGHT     0x2c
#define NAND_CMD_UNLOCK1        0x23
#define NAND_CMD_UNLOCK2        0x24
#define NAND_CMD_LOCK_STATUS    0x7a

/**
 * 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->priv;

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

        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;
        }

        /* 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 (muss 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_LOCK:  page locked
 *                        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->priv;

        /* 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_LOCK
                                          | 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 nand->writesize)
 *
 * @return              0 on success, -1 in case of error
 */
int nand_unlock(struct mtd_info *mtd, ulong start, ulong length)
{
        int ret = 0;
        int chipnr;
        int status;
        int page;
        struct nand_chip *chip = mtd->priv;
        printf ("nand_unlock: start: %08x, length: %d!\n",
                (int)start, (int)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;
        }

        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 */
        page = (int)(start >> chip->page_shift);
        chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);

        /* submit ADDRESS of LAST page to unlock */
        page += (int)(length >> chip->page_shift);
        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 nand NAND device
 * @param offset offset in flash
 * @param length image 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(nand_info_t *nand, loff_t offset, size_t length)
{
        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 >= nand->size)
                        return -1;

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

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

                offset += block_len;
        }

        return ret;
}

#ifdef CONFIG_CMD_NAND_TRIMFFS
static size_t drop_ffs(const nand_info_t *nand, const u_char *buf,
                        const size_t *len)
{
        size_t i, l = *len;

        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 + nand->writesize - 1) / nand->writesize;
        l *=  nand->writesize;

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

/**
 * 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.
 *
 * @param nand          NAND device
 * @param offset        offset in flash
 * @param length        buffer length
 * @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(nand_info_t *nand, loff_t offset, size_t *length,
                        u_char *buffer, int flags)
{
        int rval = 0, blocksize;
        size_t left_to_write = *length;
        u_char *p_buffer = buffer;
        int need_skip;

#ifdef CONFIG_CMD_NAND_YAFFS
        if (flags & WITH_YAFFS_OOB) {
                if (flags & ~WITH_YAFFS_OOB)
                        return -EINVAL;

                int pages;
                pages = nand->erasesize / nand->writesize;
                blocksize = (pages * nand->oobsize) + nand->erasesize;
                if (*length % (nand->writesize + nand->oobsize)) {
                        printf ("Attempt to write incomplete page"
                                " in yaffs mode\n");
                        return -EINVAL;
                }
        } else
#endif
        {
                blocksize = nand->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 & (nand->writesize - 1)) != 0) {
                printf ("Attempt to write non page aligned data\n");
                *length = 0;
                return -EINVAL;
        }

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

        if (!need_skip && !(flags & WITH_DROP_FFS)) {
                rval = nand_write (nand, 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) {
                size_t block_offset = offset & (nand->erasesize - 1);
                size_t write_size, truncated_write_size;

                WATCHDOG_RESET ();

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

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

#ifdef CONFIG_CMD_NAND_YAFFS
                if (flags & WITH_YAFFS_OOB) {
                        int page, pages;
                        size_t pagesize = nand->writesize;
                        size_t pagesize_oob = pagesize + nand->oobsize;
                        struct mtd_oob_ops ops;

                        ops.len = pagesize;
                        ops.ooblen = nand->oobsize;
                        ops.mode = MTD_OOB_AUTO;
                        ops.ooboffs = 0;

                        pages = write_size / pagesize_oob;
                        for (page = 0; page < pages; page++) {
                                WATCHDOG_RESET();

                                ops.datbuf = p_buffer;
                                ops.oobbuf = ops.datbuf + pagesize;

                                rval = nand->write_oob(nand, offset, &ops);
                                if (!rval)
                                        break;

                                offset += pagesize;
                                p_buffer += pagesize_oob;
                        }
                }
                else
#endif
                {
                        truncated_write_size = write_size;
#ifdef CONFIG_CMD_NAND_TRIMFFS
                        if (flags & WITH_DROP_FFS)
                                truncated_write_size = drop_ffs(nand, p_buffer,
                                                &write_size);
#endif

                        rval = nand_write(nand, 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 readen
 * instead as long as the image is short enough to fit even after skipping the
 * bad blocks.
 *
 * @param nand NAND device
 * @param offset offset in flash
 * @param length buffer length, on return holds remaining bytes to read
 * @param buffer buffer to write to
 * @return 0 in case of success
 */
int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
                       u_char *buffer)
{
        int rval;
        size_t left_to_read = *length;
        u_char *p_buffer = buffer;
        int need_skip;

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

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

        if (!need_skip) {
                rval = nand_read (nand, 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 & (nand->erasesize - 1);
                size_t read_length;

                WATCHDOG_RESET ();

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

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

                rval = nand_read (nand, 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;
}