/*
 * (C) Copyright 2000-2010
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2008
 * Stuart Wood, Lab X Technologies <stuart.wood@labxtechnologies.com>
 *
 * (C) Copyright 2004
 * Jian Zhang, Texas Instruments, jzhang@ti.com.
 *
 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Andreas Heppel <aheppel@sysgo.de>
 *
 * 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 as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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
 */

#include <common.h>
#include <command.h>
#include <environment.h>
#include <linux/stddef.h>
#include <malloc.h>
#include <nand.h>
#include <search.h>
#include <errno.h>

#if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_NAND)
#define CMD_SAVEENV
#elif defined(CONFIG_ENV_OFFSET_REDUND)
#error CONFIG_ENV_OFFSET_REDUND must have CONFIG_CMD_SAVEENV & CONFIG_CMD_NAND
#endif

#if defined(CONFIG_ENV_SIZE_REDUND) &&  \
        (CONFIG_ENV_SIZE_REDUND != CONFIG_ENV_SIZE)
#error CONFIG_ENV_SIZE_REDUND should be the same as CONFIG_ENV_SIZE
#endif

#ifndef CONFIG_ENV_RANGE
#define CONFIG_ENV_RANGE        CONFIG_ENV_SIZE
#endif

char *env_name_spec = "NAND";

#if defined(ENV_IS_EMBEDDED)
env_t *env_ptr = &environment;
#elif defined(CONFIG_NAND_ENV_DST)
env_t *env_ptr = (env_t *)CONFIG_NAND_ENV_DST;
#else /* ! ENV_IS_EMBEDDED */
env_t *env_ptr;
#endif /* ENV_IS_EMBEDDED */

DECLARE_GLOBAL_DATA_PTR;

/*
 * This is called before nand_init() so we can't read NAND to
 * validate env data.
 *
 * Mark it OK for now. env_relocate() in env_common.c will call our
 * relocate function which does the real validation.
 *
 * When using a NAND boot image (like sequoia_nand), the environment
 * can be embedded or attached to the U-Boot image in NAND flash.
 * This way the SPL loads not only the U-Boot image from NAND but
 * also the environment.
 */
int env_init(void)
{
#if defined(ENV_IS_EMBEDDED) || defined(CONFIG_NAND_ENV_DST)
        int crc1_ok = 0, crc2_ok = 0;
        env_t *tmp_env1;

#ifdef CONFIG_ENV_OFFSET_REDUND
        env_t *tmp_env2;

        tmp_env2 = (env_t *)((ulong)env_ptr + CONFIG_ENV_SIZE);
        crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) == tmp_env2->crc;
#endif
        tmp_env1 = env_ptr;
        crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == tmp_env1->crc;

        if (!crc1_ok && !crc2_ok) {
                gd->env_addr    = 0;
                gd->env_valid   = 0;

                return 0;
        } else if (crc1_ok && !crc2_ok) {
                gd->env_valid = 1;
        }
#ifdef CONFIG_ENV_OFFSET_REDUND
        else if (!crc1_ok && crc2_ok) {
                gd->env_valid = 2;
        } else {
                /* both ok - check serial */
                if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
                        gd->env_valid = 2;
                else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
                        gd->env_valid = 1;
                else if (tmp_env1->flags > tmp_env2->flags)
                        gd->env_valid = 1;
                else if (tmp_env2->flags > tmp_env1->flags)
                        gd->env_valid = 2;
                else /* flags are equal - almost impossible */
                        gd->env_valid = 1;
        }

        if (gd->env_valid == 2)
                env_ptr = tmp_env2;
        else
#endif
        if (gd->env_valid == 1)
                env_ptr = tmp_env1;

        gd->env_addr = (ulong)env_ptr->data;

#else /* ENV_IS_EMBEDDED || CONFIG_NAND_ENV_DST */
        gd->env_addr    = (ulong)&default_environment[0];
        gd->env_valid   = 1;
#endif /* ENV_IS_EMBEDDED || CONFIG_NAND_ENV_DST */

        return 0;
}

#ifdef CMD_SAVEENV
/*
 * The legacy NAND code saved the environment in the first NAND device i.e.,
 * nand_dev_desc + 0. This is also the behaviour using the new NAND code.
 */
int writeenv(size_t offset, u_char *buf)
{
        size_t end = offset + CONFIG_ENV_RANGE;
        size_t amount_saved = 0;
        size_t blocksize, len;
        u_char *char_ptr;

        blocksize = nand_info[0].erasesize;
        len = min(blocksize, CONFIG_ENV_SIZE);

        while (amount_saved < CONFIG_ENV_SIZE && offset < end) {
                if (nand_block_isbad(&nand_info[0], offset)) {
                        offset += blocksize;
                } else {
                        char_ptr = &buf[amount_saved];
                        if (nand_write(&nand_info[0], offset, &len, char_ptr))
                                return 1;

                        offset += blocksize;
                        amount_saved += len;
                }
        }
        if (amount_saved != CONFIG_ENV_SIZE)
                return 1;

        return 0;
}

#ifdef CONFIG_ENV_OFFSET_REDUND
static unsigned char env_flags;

int saveenv(void)
{
        env_t   env_new;
        ssize_t len;
        char    *res;
        int     ret = 0;
        nand_erase_options_t nand_erase_options;

        memset(&nand_erase_options, 0, sizeof(nand_erase_options));
        nand_erase_options.length = CONFIG_ENV_RANGE;

        if (CONFIG_ENV_RANGE < CONFIG_ENV_SIZE)
                return 1;

        res = (char *)&env_new.data;
        len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
        if (len < 0) {
                error("Cannot export environment: errno = %d\n", errno);
                return 1;
        }
        env_new.crc     = crc32(0, env_new.data, ENV_SIZE);
        env_new.flags   = ++env_flags; /* increase the serial */

        if (gd->env_valid == 1) {
                puts("Erasing redundant NAND...\n");
                nand_erase_options.offset = CONFIG_ENV_OFFSET_REDUND;
                if (nand_erase_opts(&nand_info[0], &nand_erase_options))
                        return 1;

                puts("Writing to redundant NAND... ");
                ret = writeenv(CONFIG_ENV_OFFSET_REDUND, (u_char *)&env_new);
        } else {
                puts("Erasing NAND...\n");
                nand_erase_options.offset = CONFIG_ENV_OFFSET;
                if (nand_erase_opts(&nand_info[0], &nand_erase_options))
                        return 1;

                puts("Writing to NAND... ");
                ret = writeenv(CONFIG_ENV_OFFSET, (u_char *)&env_new);
        }
        if (ret) {
                puts("FAILED!\n");
                return 1;
        }

        puts("done\n");

        gd->env_valid = gd->env_valid == 2 ? 1 : 2;

        return ret;
}
#else /* ! CONFIG_ENV_OFFSET_REDUND */
int saveenv(void)
{
        int     ret = 0;
        ALLOC_CACHE_ALIGN_BUFFER(env_t, env_new, 1);
        ssize_t len;
        char    *res;
        nand_erase_options_t nand_erase_options;

        memset(&nand_erase_options, 0, sizeof(nand_erase_options));
        nand_erase_options.length = CONFIG_ENV_RANGE;
        nand_erase_options.offset = CONFIG_ENV_OFFSET;

        if (CONFIG_ENV_RANGE < CONFIG_ENV_SIZE)
                return 1;

        res = (char *)&env_new->data;
        len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
        if (len < 0) {
                error("Cannot export environment: errno = %d\n", errno);
                return 1;
        }
        env_new->crc = crc32(0, env_new->data, ENV_SIZE);

        puts("Erasing Nand...\n");
        if (nand_erase_opts(&nand_info[0], &nand_erase_options))
                return 1;

        puts("Writing to Nand... ");
        if (writeenv(CONFIG_ENV_OFFSET, (u_char *)env_new)) {
                puts("FAILED!\n");
                return 1;
        }

        puts("done\n");
        return ret;
}
#endif /* CONFIG_ENV_OFFSET_REDUND */
#endif /* CMD_SAVEENV */

int readenv(size_t offset, u_char *buf)
{
        size_t end = offset + CONFIG_ENV_RANGE;
        size_t amount_loaded = 0;
        size_t blocksize, len;
        u_char *char_ptr;

        blocksize = nand_info[0].erasesize;
        if (!blocksize)
                return 1;

        len = min(blocksize, CONFIG_ENV_SIZE);

        while (amount_loaded < CONFIG_ENV_SIZE && offset < end) {
                if (nand_block_isbad(&nand_info[0], offset)) {
                        offset += blocksize;
                } else {
                        char_ptr = &buf[amount_loaded];
                        if (nand_read_skip_bad(&nand_info[0], offset,
                                               &len, NULL,
                                               nand_info[0].size, char_ptr))
                                return 1;

                        offset += blocksize;
                        amount_loaded += len;
                }
        }

        if (amount_loaded != CONFIG_ENV_SIZE)
                return 1;

        return 0;
}

#ifdef CONFIG_ENV_OFFSET_OOB
int get_nand_env_oob(nand_info_t *nand, unsigned long *result)
{
        struct mtd_oob_ops ops;
        uint32_t oob_buf[ENV_OFFSET_SIZE / sizeof(uint32_t)];
        int ret;

        ops.datbuf      = NULL;
        ops.mode        = MTD_OOB_AUTO;
        ops.ooboffs     = 0;
        ops.ooblen      = ENV_OFFSET_SIZE;
        ops.oobbuf      = (void *)oob_buf;

        ret = nand->read_oob(nand, ENV_OFFSET_SIZE, &ops);
        if (ret) {
                printf("error reading OOB block 0\n");
                return ret;
        }

        if (oob_buf[0] == ENV_OOB_MARKER) {
                *result = oob_buf[1] * nand->erasesize;
        } else if (oob_buf[0] == ENV_OOB_MARKER_OLD) {
                *result = oob_buf[1];
        } else {
                printf("No dynamic environment marker in OOB block 0\n");
                return -ENOENT;
        }

        return 0;
}
#endif

#ifdef CONFIG_ENV_OFFSET_REDUND
void env_relocate_spec(void)
{
#if !defined(ENV_IS_EMBEDDED)
        int read1_fail = 0, read2_fail = 0;
        int crc1_ok = 0, crc2_ok = 0;
        env_t *ep, *tmp_env1, *tmp_env2;

        tmp_env1 = (env_t *)malloc(CONFIG_ENV_SIZE);
        tmp_env2 = (env_t *)malloc(CONFIG_ENV_SIZE);
        if (tmp_env1 == NULL || tmp_env2 == NULL) {
                puts("Can't allocate buffers for environment\n");
                set_default_env("!malloc() failed");
                goto done;
        }

        read1_fail = readenv(CONFIG_ENV_OFFSET, (u_char *) tmp_env1);
        read2_fail = readenv(CONFIG_ENV_OFFSET_REDUND, (u_char *) tmp_env2);

        if (read1_fail && read2_fail)
                puts("*** Error - No Valid Environment Area found\n");
        else if (read1_fail || read2_fail)
                puts("*** Warning - some problems detected "
                     "reading environment; recovered successfully\n");

        crc1_ok = !read1_fail &&
                (crc32(0, tmp_env1->data, ENV_SIZE) == tmp_env1->crc);
        crc2_ok = !read2_fail &&
                (crc32(0, tmp_env2->data, ENV_SIZE) == tmp_env2->crc);

        if (!crc1_ok && !crc2_ok) {
                set_default_env("!bad CRC");
                goto done;
        } else if (crc1_ok && !crc2_ok) {
                gd->env_valid = 1;
        } else if (!crc1_ok && crc2_ok) {
                gd->env_valid = 2;
        } else {
                /* both ok - check serial */
                if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
                        gd->env_valid = 2;
                else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
                        gd->env_valid = 1;
                else if (tmp_env1->flags > tmp_env2->flags)
                        gd->env_valid = 1;
                else if (tmp_env2->flags > tmp_env1->flags)
                        gd->env_valid = 2;
                else /* flags are equal - almost impossible */
                        gd->env_valid = 1;
        }

        free(env_ptr);

        if (gd->env_valid == 1)
                ep = tmp_env1;
        else
                ep = tmp_env2;

        env_flags = ep->flags;
        env_import((char *)ep, 0);

done:
        free(tmp_env1);
        free(tmp_env2);

#endif /* ! ENV_IS_EMBEDDED */
}
#else /* ! CONFIG_ENV_OFFSET_REDUND */
/*
 * The legacy NAND code saved the environment in the first NAND
 * device i.e., nand_dev_desc + 0. This is also the behaviour using
 * the new NAND code.
 */
void env_relocate_spec(void)
{
#if !defined(ENV_IS_EMBEDDED)
        int ret;
        ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);

#if defined(CONFIG_ENV_OFFSET_OOB)
        ret = get_nand_env_oob(&nand_info[0], &nand_env_oob_offset);
        /*
         * If unable to read environment offset from NAND OOB then fall through
         * to the normal environment reading code below
         */
        if (!ret) {
                printf("Found Environment offset in OOB..\n");
        } else {
                set_default_env("!no env offset in OOB");
                return;
        }
#endif

        ret = readenv(CONFIG_ENV_OFFSET, (u_char *)buf);
        if (ret) {
                set_default_env("!readenv() failed");
                return;
        }

        env_import(buf, 1);
#endif /* ! ENV_IS_EMBEDDED */
}
#endif /* CONFIG_ENV_OFFSET_REDUND */