zephyr/include/fcb.h

147 lines
3.7 KiB
C

/*
* Copyright (c) 2017 Nordic Semiconductor ASA
* Copyright (c) 2015 Runtime Inc
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef __FCB_H_
#define __FCB_H_
#ifdef __cplusplus
extern "C" {
#endif
/*
* Flash circular buffer.
*/
#include <inttypes.h>
#include <limits.h>
#include "flash_map.h"
#include <kernel.h>
#define FCB_MAX_LEN (CHAR_MAX | CHAR_MAX << 7) /* Max length of element */
/*
* Entry location is pointer to area (within fcb->f_sectors), and offset
* within that area.
*/
struct fcb_entry {
struct flash_sector *fe_sector; /* ptr to sector */
/* within fcb->f_sectors */
u32_t fe_elem_off; /* start of entry */
u32_t fe_data_off; /* start of data */
u16_t fe_data_len; /* size of data area */
};
/*
* Helper macro for calculate the data offset related to
* the fcb flash_area start offset.
*/
#define FCB_ENTRY_FA_DATA_OFF(entry) (entry.fe_sector->fs_off +\
entry.fe_data_off)
struct fcb_entry_ctx {
struct fcb_entry loc;
const struct flash_area *fap;
};
struct fcb {
/* Caller of fcb_init fills this in */
u32_t f_magic; /* As placed on the disk */
u8_t f_version; /* Current version number of the data */
u8_t f_sector_cnt; /* Number of elements in sector array */
u8_t f_scratch_cnt; /* How many sectors should be kept empty */
struct flash_sector *f_sectors; /* Array of sectors, */
/* must be contiguous */
/* Flash circular buffer internal state */
struct k_mutex f_mtx; /* Locking for accessing the FCB data */
struct flash_sector *f_oldest;
struct fcb_entry f_active;
u16_t f_active_id;
u8_t f_align; /* writes to flash have to aligned to this */
const struct flash_area *fap; /* Flash area used by the fcb instance */
/* This can be transfer to FCB user */
};
/*
* Error codes.
*/
#define FCB_OK 0
#define FCB_ERR_ARGS -1
#define FCB_ERR_FLASH -2
#define FCB_ERR_NOVAR -3
#define FCB_ERR_NOSPACE -4
#define FCB_ERR_NOMEM -5
#define FCB_ERR_CRC -6
#define FCB_ERR_MAGIC -7
int fcb_init(int f_area_id, struct fcb *fcb);
/*
* fcb_append() appends an entry to circular buffer. When writing the
* contents for the entry, use loc->fl_area and loc->fl_data_off with
* flash_area_write(). When you're finished, call fcb_append_finish() with
* loc as argument.
*/
int fcb_append(struct fcb *fcb, u16_t len, struct fcb_entry *loc);
int fcb_append_finish(struct fcb *fcb, struct fcb_entry *append_loc);
/*
* Walk over all log entries in FCB, or entries in a given flash_area.
* cb gets called for every entry. If cb wants to stop the walk, it should
* return non-zero value.
*
* Entry data can be read using flash_area_read(), using
* loc->fe_area, loc->fe_data_off, and loc->fe_data_len as arguments.
*/
typedef int (*fcb_walk_cb)(struct fcb_entry_ctx *loc_ctx, void *arg);
int fcb_walk(struct fcb *fcb, struct flash_sector *sector, fcb_walk_cb cb,
void *cb_arg);
int fcb_getnext(struct fcb *fcb, struct fcb_entry *loc);
/*
* Erases the data from oldest sector.
*/
int fcb_rotate(struct fcb *fcb);
/*
* Start using the scratch block.
*/
int fcb_append_to_scratch(struct fcb *fcb);
/*
* How many sectors are unused.
*/
int fcb_free_sector_cnt(struct fcb *fcb);
/*
* Whether FCB has any data.
*/
int fcb_is_empty(struct fcb *fcb);
/*
* Element at offset *entries* from last position (backwards).
*/
int fcb_offset_last_n(struct fcb *fcb, u8_t entries,
struct fcb_entry *last_n_entry);
/*
* Clears FCB passed to it
*/
int fcb_clear(struct fcb *fcb);
int fcb_flash_read(const struct fcb *fcb, const struct flash_sector *sector,
off_t off, void *dst, size_t len);
int fcb_flash_write(const struct fcb *fcb, const struct flash_sector *sector,
off_t off, const void *src, size_t len);
#ifdef __cplusplus
}
#endif
#endif /* __FCB_H_ */