/*
 * Copyright (c) 2010 Broadcom Corporation
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _bcmnvram_h_
#define _bcmnvram_h_

#ifndef _LANGUAGE_ASSEMBLY

#include <bcmdefs.h>

struct nvram_header {
	u32 magic;
	u32 len;
	u32 crc_ver_init;	/* 0:7 crc, 8:15 ver, 16:31 sdram_init */
	u32 config_refresh;	/* 0:15 sdram_config, 16:31 sdram_refresh */
	u32 config_ncdl;	/* ncdl values for memc */
};

/*
 * Initialize NVRAM access. May be unnecessary or undefined on certain
 * platforms.
 */
extern int nvram_init(void);

/*
 * Append a chunk of nvram variables to the global list
 */
extern int nvram_append(char *vars, uint varsz);

/*
 * Check for reset button press for restoring factory defaults.
 */
extern int nvram_reset(void);

/*
 * Disable NVRAM access. May be unnecessary or undefined on certain
 * platforms.
 */
extern void nvram_exit(void);

/*
 * Get the value of an NVRAM variable. The pointer returned may be
 * invalid after a set.
 * @param	name	name of variable to get
 * @return	value of variable or NULL if undefined
 */
extern char *nvram_get(const char *name);

/*
 * Get the value of an NVRAM variable.
 * @param	name	name of variable to get
 * @return	value of variable or NUL if undefined
 */
#define nvram_safe_get(name) (nvram_get(name) ? : "")

/*
 * Match an NVRAM variable.
 * @param	name	name of variable to match
 * @param	match	value to compare against value of variable
 * @return	true if variable is defined and its value is string equal
 *		to match or false otherwise
 */
static inline int nvram_match(char *name, char *match)
{
	const char *value = nvram_get(name);
	return value && !strcmp(value, match);
}

/*
 * Inversely match an NVRAM variable.
 * @param	name	name of variable to match
 * @param	match	value to compare against value of variable
 * @return	true if variable is defined and its value is not string
 *		equal to invmatch or false otherwise
 */
static inline int nvram_invmatch(char *name, char *invmatch)
{
	const char *value = nvram_get(name);
	return value && strcmp(value, invmatch);
}

/*
 * Set the value of an NVRAM variable. The name and value strings are
 * copied into private storage. Pointers to previously set values
 * may become invalid. The new value may be immediately
 * retrieved but will not be permanently stored until a commit.
 * @param	name	name of variable to set
 * @param	value	value of variable
 * @return	0 on success and errno on failure
 */
extern int nvram_set(const char *name, const char *value);

/*
 * Unset an NVRAM variable. Pointers to previously set values
 * remain valid until a set.
 * @param	name	name of variable to unset
 * @return	0 on success and errno on failure
 * NOTE: use nvram_commit to commit this change to flash.
 */
extern int nvram_unset(const char *name);

/*
 * Commit NVRAM variables to permanent storage. All pointers to values
 * may be invalid after a commit.
 * NVRAM values are undefined after a commit.
 * @return	0 on success and errno on failure
 */
extern int nvram_commit(void);

/*
 * Get all NVRAM variables (format name=value\0 ... \0\0).
 * @param	buf	buffer to store variables
 * @param	count	size of buffer in bytes
 * @return	0 on success and errno on failure
 */
extern int nvram_getall(char *nvram_buf, int count);

#endif				/* _LANGUAGE_ASSEMBLY */

/* variable access */
extern char *getvar(char *vars, const char *name);
extern int getintvar(char *vars, const char *name);

/* The NVRAM version number stored as an NVRAM variable */
#define NVRAM_SOFTWARE_VERSION	"1"

#define NVRAM_MAGIC		0x48534C46	/* 'FLSH' */
#define NVRAM_CLEAR_MAGIC	0x0
#define NVRAM_INVALID_MAGIC	0xFFFFFFFF
#define NVRAM_VERSION		1
#define NVRAM_HEADER_SIZE	20
#define NVRAM_SPACE		0x8000

#define NVRAM_MAX_VALUE_LEN 255
#define NVRAM_MAX_PARAM_LEN 64

#define NVRAM_CRC_START_POSITION	9	/* magic, len, crc8 to be skipped */
#define NVRAM_CRC_VER_MASK	0xffffff00	/* for crc_ver_init */

#endif				/* _bcmnvram_h_ */