/*

   * (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>

   *

   * SPDX-License-Identifier:	GPL-2.0+

   */

  #include <common.h>

  #include <command.h>
  #include <environment.h>
  #include <linux/stddef.h>

  #include <malloc.h>

  #include <memalign.h>

  #include <nand.h>

  #include <search.h>
  #include <errno.h>

  #if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_NAND) && \
  		!defined(CONFIG_SPL_BUILD)

  #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

  #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.

   */

  static int env_nand_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	= ENV_INVALID;

  
  		return 0;
  	} else if (crc1_ok && !crc2_ok) {

  		gd->env_valid = ENV_VALID;

  	}
  #ifdef CONFIG_ENV_OFFSET_REDUND
  	else if (!crc1_ok && crc2_ok) {

  		gd->env_valid = ENV_REDUND;

  	} else {

  		/* both ok - check serial */

  		if (tmp_env1->flags == 255 && tmp_env2->flags == 0)

  			gd->env_valid = ENV_REDUND;

  		else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)

  			gd->env_valid = ENV_VALID;

  		else if (tmp_env1->flags > tmp_env2->flags)

  			gd->env_valid = ENV_VALID;

  		else if (tmp_env2->flags > tmp_env1->flags)

  			gd->env_valid = ENV_REDUND;

  		else /* flags are equal - almost impossible */

  			gd->env_valid = ENV_VALID;

  	}

  	if (gd->env_valid == ENV_REDUND)

  		env_ptr = tmp_env2;
  	else
  #endif

  	if (gd->env_valid == ENV_VALID)

  		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	= ENV_VALID;

  #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.
   */

  static int writeenv(size_t offset, u_char *buf)

  {

  	size_t end = offset + CONFIG_ENV_RANGE;

  	size_t amount_saved = 0;

  	size_t blocksize, len;

  	struct mtd_info *mtd;

  	u_char *char_ptr;

  	mtd = get_nand_dev_by_index(0);
  	if (!mtd)
  		return 1;
  
  	blocksize = mtd->erasesize;

  	len = min(blocksize, (size_t)CONFIG_ENV_SIZE);

  	while (amount_saved < CONFIG_ENV_SIZE && offset < end) {

  		if (nand_block_isbad(mtd, offset)) {

  			offset += blocksize;
  		} else {
  			char_ptr = &buf[amount_saved];

  			if (nand_write(mtd, offset, &len, char_ptr))

  				return 1;

  			offset += blocksize;

  			amount_saved += len;

  		}
  	}

  	if (amount_saved != CONFIG_ENV_SIZE)

  		return 1;
  
  	return 0;
  }

  struct nand_env_location {

  	const char *name;
  	const nand_erase_options_t erase_opts;
  };

  static int erase_and_write_env(const struct nand_env_location *location,

  		u_char *env_new)

  {

  	struct mtd_info *mtd;

  	int ret = 0;

  	mtd = get_nand_dev_by_index(0);
  	if (!mtd)

  		return 1;

  	printf("Erasing %s...
  ", location->name);

  	if (nand_erase_opts(mtd, &location->erase_opts))

  		return 1;

  	printf("Writing to %s... ", location->name);
  	ret = writeenv(location->erase_opts.offset, env_new);
  	puts(ret ? "FAILED!
  " : "OK
  ");

  	return ret;
  }

  static int env_nand_save(void)

  {

  	int	ret = 0;

  	ALLOC_CACHE_ALIGN_BUFFER(env_t, env_new, 1);

  	int	env_idx = 0;

  	static const struct nand_env_location location[] = {

  		{
  			.name = "NAND",
  			.erase_opts = {
  				.length = CONFIG_ENV_RANGE,
  				.offset = CONFIG_ENV_OFFSET,
  			},
  		},
  #ifdef CONFIG_ENV_OFFSET_REDUND
  		{
  			.name = "redundant NAND",
  			.erase_opts = {
  				.length = CONFIG_ENV_RANGE,
  				.offset = CONFIG_ENV_OFFSET_REDUND,
  			},
  		},
  #endif
  	};

  	if (CONFIG_ENV_RANGE < CONFIG_ENV_SIZE)

  		return 1;

  	ret = env_export(env_new);
  	if (ret)
  		return ret;

  #ifdef CONFIG_ENV_OFFSET_REDUND

  	env_idx = (gd->env_valid == ENV_VALID);

  #endif

  	ret = erase_and_write_env(&location[env_idx], (u_char *)env_new);
  #ifdef CONFIG_ENV_OFFSET_REDUND
  	if (!ret) {
  		/* preset other copy for next write */

  		gd->env_valid = gd->env_valid == ENV_REDUND ? ENV_VALID :
  				ENV_REDUND;

  		return ret;

  	}

  	env_idx = (env_idx + 1) & 1;
  	ret = erase_and_write_env(&location[env_idx], (u_char *)env_new);
  	if (!ret)
  		printf("Warning: primary env write failed,"
  				" redundancy is lost!
  ");
  #endif

  	return ret;

  }
  #endif /* CMD_SAVEENV */

  #if defined(CONFIG_SPL_BUILD)
  static int readenv(size_t offset, u_char *buf)
  {
  	return nand_spl_load_image(offset, CONFIG_ENV_SIZE, buf);
  }
  #else

  static int readenv(size_t offset, u_char *buf)

  {

  	size_t end = offset + CONFIG_ENV_RANGE;

  	size_t amount_loaded = 0;

  	size_t blocksize, len;

  	struct mtd_info *mtd;

  	u_char *char_ptr;

  	mtd = get_nand_dev_by_index(0);
  	if (!mtd)

  		return 1;

  	blocksize = mtd->erasesize;

  	len = min(blocksize, (size_t)CONFIG_ENV_SIZE);

  	while (amount_loaded < CONFIG_ENV_SIZE && offset < end) {

  		if (nand_block_isbad(mtd, offset)) {

  			offset += blocksize;
  		} else {
  			char_ptr = &buf[amount_loaded];

  			if (nand_read_skip_bad(mtd, offset,

  					       &len, NULL,

  					       mtd->size, char_ptr))

  				return 1;

  			offset += blocksize;

  			amount_loaded += len;

  		}
  	}

  	if (amount_loaded != CONFIG_ENV_SIZE)

  		return 1;
  
  	return 0;
  }

  #endif /* #if defined(CONFIG_SPL_BUILD) */

  #ifdef CONFIG_ENV_OFFSET_OOB

  int get_nand_env_oob(struct mtd_info *mtd, 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 = mtd->read_oob(mtd, ENV_OFFSET_SIZE, &ops);

  	if (ret) {
  		printf("error reading OOB block 0
  ");
  		return ret;
  	}

  	if (oob_buf[0] == ENV_OOB_MARKER) {

  		*result = ovoid ob_buf[1] * mtd->erasesize;

  	} else if (oob_buf[0] == ENV_OOB_MARKER_OLD) {
  		*result = oob_buf[1];

  	} else {

  		printf("No dynamic environment marker in OOB block 0
  ");
  		return -ENOENT;

  	}

  
  	return 0;

  }
  #endif

  #ifdef CONFIG_ENV_OFFSET_REDUND

  static int env_nand_load(void)

  {

  #if defined(ENV_IS_EMBEDDED)
  	return 0;
  #else

  	int read1_fail, read2_fail;

  	env_t *tmp_env1, *tmp_env2;

  	int ret = 0;

  	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
  ");

  		set_default_env("!malloc() failed");

  		ret = -EIO;

  		goto done;

  	}

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

  	ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2,
  				read2_fail);

  done:

  	free(tmp_env1);
  	free(tmp_env2);

  	return ret;

  #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.

   */

  static int env_nand_load(void)

  {
  #if !defined(ENV_IS_EMBEDDED)

  	int ret;

  	ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);

  #if defined(CONFIG_ENV_OFFSET_OOB)

  	struct mtd_info *mtd  = get_nand_dev_by_index(0);

  	/*
  	 * If unable to read environment offset from NAND OOB then fall through

  	 * to the normal environment reading code below
  	 */

  	if (mtd && !get_nand_env_oob(mtd, &nand_env_oob_offset)) {

  		printf("Found Environment offset in OOB..
  ");

  	} 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 -EIO;

  	}

  	return env_import(buf, 1);

  #endif /* ! ENV_IS_EMBEDDED */

  
  	return 0;

  }

  #endif /* CONFIG_ENV_OFFSET_REDUND */

  
  U_BOOT_ENV_LOCATION(nand) = {
  	.location	= ENVL_NAND,

  	ENV_NAME("NAND")

  	.load		= env_nand_load,

  #if defined(CMD_SAVEENV)

  	.save		= env_save_ptr(env_nand_save),

  #endif

  	.init		= env_nand_init,

  };