1 /* 2 * Copyright (c) 2019 Laczen 3 * Copyright (c) 2019 Nordic Semiconductor ASA 4 * 5 * SPDX-License-Identifier: Apache-2.0 6 */ 7 8 #ifndef __SETTINGS_NVS_H_ 9 #define __SETTINGS_NVS_H_ 10 11 #include <zephyr/fs/nvs.h> 12 #include <zephyr/settings/settings.h> 13 14 #ifdef __cplusplus 15 extern "C" { 16 #endif 17 18 /* In the NVS backend, each setting is stored in two NVS entries: 19 * 1. setting's name 20 * 2. setting's value 21 * 22 * The NVS entry ID for the setting's value is determined implicitly based on 23 * the ID of the NVS entry for the setting's name, once that is found. The 24 * difference between name and value ID is constant and equal to 25 * NVS_NAME_ID_OFFSET. 26 * 27 * Setting's name entries start from NVS_NAMECNT_ID + 1. The entry at 28 * NVS_NAMECNT_ID is used to store the largest name ID in use. 29 * 30 * Deleted records will not be found, only the last record will be 31 * read. 32 */ 33 #define NVS_NAMECNT_ID 0x8000 34 #define NVS_NAME_ID_OFFSET 0x4000 35 36 struct settings_nvs { 37 struct settings_store cf_store; 38 struct nvs_fs cf_nvs; 39 uint16_t last_name_id; 40 const struct device *flash_dev; 41 #if CONFIG_SETTINGS_NVS_NAME_CACHE 42 struct { 43 uint16_t name_hash; 44 uint16_t name_id; 45 } cache[CONFIG_SETTINGS_NVS_NAME_CACHE_SIZE]; 46 47 uint16_t cache_next; 48 uint16_t cache_total; 49 bool loaded; 50 #endif 51 }; 52 53 /* register nvs to be a source of settings */ 54 int settings_nvs_src(struct settings_nvs *cf); 55 56 /* register nvs to be the destination of settings */ 57 int settings_nvs_dst(struct settings_nvs *cf); 58 59 /* Initialize a nvs backend. */ 60 int settings_nvs_backend_init(struct settings_nvs *cf); 61 62 63 #ifdef __cplusplus 64 } 65 #endif 66 67 #endif /* __SETTINGS_NVS_H_ */ 68
