/* Reflow Oven Controller
*
* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
*
* This file is part of the Reflow Oven Controller Project.
*
* The reflow oven controller 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.
*
* The Reflow Oven Control Firmware 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 the reflow oven controller project.
* If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef __SAFETY_MEMORY_H__
#define __SAFETY_MEMORY_H__

#include <stdint.h>

/**
 * @brief Magic number to signal a valid safety memory header.
 */
#define SAFETY_MEMORY_MAGIC 0x12AA5CB7

/**
 * @brief Offset address for the safety_memory_header.
 * @note Any other value than 0UL doesn't really make sense. Therfore, this should not be changed.
 */
#define SAFETY_MEMORY_HEADER_ADDRESS 0UL

#define SAFETY_MEMORY_CONFIG_OVERRIDE_COUNT 32UL

/**
 * @brief Safety memory header
 */
struct safety_memory_header {
	uint32_t magic;			/**< @brief Magic. Set to @ref SAFETY_MEMORY_MAGIC */
	uint32_t boot_status_offset;	/**< @brief Offset of the safety_memory_boot_status struct (in 32 bit words)*/
	uint32_t config_overrides_offset; /**< @brief Offset address of override entries */
	uint32_t config_overrides_len;	/**< @brief Length of override entries in words */
	uint32_t err_memory_offset;	/**< @brief Offset of the error memory */
	uint32_t err_memory_end;	/**< @brief End of the error memory. This points to the word after the error memory, containing the CRC of the whole backup RAM. */
	uint32_t magic_i;		/**< @brief Invers Magic. Set to the bitwise inverse of @ref SAFETY_MEMORY_MAGIC */
};

struct safety_memory_boot_status {
	uint32_t reboot_to_bootloader;
	uint32_t code_updated;
	uint32_t reset_from_panic;
};

enum safety_memory_state {
	SAFETY_MEMORY_INIT_FRESH = 0,
	SAFETY_MEMORY_INIT_CORRUPTED = 1,
	SAFETY_MEMORY_INIT_VALID_MEMORY = 2,
};

enum safety_memory_error_entry_type {
	SAFETY_MEMORY_ERR_ENTRY_FLAG = 1,
	SAFETY_MEMORY_ERR_ENTRY_NOP = 2,
};

struct error_memory_entry {
	enum safety_memory_error_entry_type type;
	uint8_t flag_num;
};

enum config_override_entry_type {
	SAFETY_MEMORY_CONFIG_OVERRIDE_WEIGHT = 1,
	SAFETY_MEMORY_CONFIG_OVERRIDE_PERSISTANCE = 2,
};

struct config_override {
	enum config_override_entry_type type;
	union {
		struct {
			uint8_t flag;
			uint8_t weight;
		} weight_override;
		struct {
			uint8_t flag;
			uint8_t persistance;
		} persistance_override;
	} entry;
};

int safety_memory_init(enum safety_memory_state *found_state);

int safety_memory_reinit(enum safety_memory_state *found_state);

int safety_memory_get_boot_status(struct safety_memory_boot_status *status);

int safety_memory_set_boot_status(const struct safety_memory_boot_status *status);

int safety_memory_get_error_entry_count(uint32_t *count);

int safety_memory_check(void);

int safety_memory_get_error_entry(uint32_t idx, struct error_memory_entry *entry);

int safety_memory_insert_error_entry(struct error_memory_entry *entry);

int safety_memory_insert_config_override(struct config_override *config_override);

int safety_memory_get_config_override_count(uint32_t *count);

int safety_memory_get_config_override(uint32_t idx, struct config_override *config_override);

#endif /* __SAFETY_MEMORY_H__ */