/*
 * (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

#ifndef CONFIG_ENV_TRY_COUNT
#define CONFIG_ENV_TRY_COUNT     1
#endif

#define WRITEENV_SUCCESS         0
#define WRITEENV_WRITE_FAIL      1
#define WRITEENV_OUT_OF_BLOCKS   2

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)) {
			printf("Skipping bad block at 0x%08x\n", offset);
			offset += blocksize;
		} else {
			char_ptr = &buf[amount_saved];
			if (nand_write(&nand_info[0], offset, &len, char_ptr))
				return WRITEENV_WRITE_FAIL;

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

	return WRITEENV_SUCCESS;
}

#ifdef CONFIG_ENV_OFFSET_REDUND
static unsigned char env_flags;

int saveenv_offset(size_t offset, u_char *buf)
{
    int ret;
    nand_erase_options_t nand_erase_options;
    int try_count = 0;
    size_t current_offset = offset;

    /* Erase whole range each time */
	memset(&nand_erase_options, 0, sizeof(nand_erase_options));
	nand_erase_options.length = CONFIG_ENV_RANGE;
    nand_erase_options.offset = offset;

    do
    {
        printf ("Erasing Nand at offset 0x%08x ...\n", offset);    
        ret = nand_erase_opts(&nand_info[0], &nand_erase_options);
        if (!ret) 
        {
            printf ("Writing Nand at offset 0x%08x ... \n", offset);
            ret = writeenv(offset, buf);
        }
		
        /* If failed and not out of blocks, retry or mark bad and move on */
        if (ret == WRITEENV_WRITE_FAIL) 
        {
            if (try_count < (CONFIG_ENV_TRY_COUNT - 1))
            {
                puts ("Retrying\n");
                try_count++;
            }
            else
            {
                printf ("Marking block 0x%08x bad\n", current_offset);
                if (nand_info[0].block_markbad(&nand_info[0], current_offset))
                {
                    printf ("block 0x%08x NOT marked as bad!\n", current_offset);
                    return 1;
				}
                else
                {
                    /* Reset number of tries */
                    try_count = 0;
                    current_offset += nand_info[0].erasesize;
                    if (current_offset == (offset + CONFIG_ENV_RANGE))
                    {
                        ret = WRITEENV_OUT_OF_BLOCKS;
                    }
                }
            }
        }
    } while (ret == WRITEENV_WRITE_FAIL);

    return ret;
}

int saveenv(void)
{
	env_t	env_new;
	ssize_t	len;
	char	*res;
	int	ret = 0;
	ulong current_offset;
	ulong second_offset;

	if (CONFIG_ENV_RANGE < CONFIG_ENV_SIZE)
		return 1;

	res = (char *)&env_new.data;
	len = hexport_r(&env_htab, '\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) {
		current_offset = CONFIG_ENV_OFFSET_REDUND;
		second_offset = CONFIG_ENV_OFFSET;
	} else {
		current_offset = CONFIG_ENV_OFFSET;
		second_offset = CONFIG_ENV_OFFSET_REDUND;
	}
        
    /* Try to save to the second region */
    printf("Trying %s region\n", 
            (second_offset == CONFIG_ENV_OFFSET_REDUND) ? "Redundant" : "Primary" );
    ret = saveenv_offset(second_offset, (u_char *)&env_new);
    if (ret) {
        printf("Out of blocks in %s region\n", 
                (second_offset == CONFIG_ENV_OFFSET_REDUND) ? "Redundant" : "Primary" );
        printf("Trying %s region\n", 
                (current_offset == CONFIG_ENV_OFFSET_REDUND) ? "Redundant" : "Primary" );
        /* If it fails, try the current one */
        ret = saveenv_offset(current_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', &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, 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 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;
	}

	if (readenv(CONFIG_ENV_OFFSET, (u_char *) tmp_env1))
		puts("No Valid Environment Area found\n");

	if (readenv(CONFIG_ENV_OFFSET_REDUND, (u_char *) tmp_env2))
		puts("No Valid Redundant Environment Area found\n");

	crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == tmp_env1->crc;
	crc2_ok = 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 */