settings: zms: code style clean up

Clean some parts of the code and refactor it to avoid multiple nested
conditions.

Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>

Author: rghaddab

include/zephyr/settings/settings.h

@@ -469,8 +469,8 @@ struct settings_store_itf {
 	/**< Loads values from storage limited to subtree defined by subtree.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node,
-	 *  - arg - Structure that holds additional data for data loading.
+	 *  - cs[in] - Corresponding backend handler node,
+	 *  - arg[in] - Structure that holds additional data for data loading.
 	 *
 	 * @note
 	 * Backend is expected not to provide duplicates of the entities.
@@ -484,50 +484,50 @@ struct settings_store_itf {
 	/**< Loads one value from storage that corresponds to the key defined by name.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node.
-	 *  - name - Key in string format.
-	 *  - buf - Buffer where data should be copied.
-	 *  - buf_len - Length of buf.
+	 *  - cs[in] - Corresponding backend handler node.
+	 *  - name[in] - Key in string format.
+	 *  - buf[in] - Buffer where data should be copied.
+	 *  - buf_len[in] - Length of buf.
 	 */
 
 	ssize_t (*csi_get_val_len)(struct settings_store *cs, const char *name);
 	/**< Gets the value's length associated to the Key defined by name.
 	 * It returns 0 if the Key/Value doesn't exist.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node.
-	 *  - name - Key in string format.
+	 *  - cs[in] - Corresponding backend handler node.
+	 *  - name[in] - Key in string format.
 	 */
 
 	int (*csi_save_start)(struct settings_store *cs);
 	/**< Handler called before an export operation.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node
+	 *  - cs[in] - Corresponding backend handler node
 	 */
 
 	int (*csi_save)(struct settings_store *cs, const char *name,
 			const char *value, size_t val_len);
 	/**< Save a single key-value pair to storage.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node
-	 *  - name - Key in string format
-	 *  - value - Binary value
-	 *  - val_len - Length of value in bytes.
+	 *  - cs[in] - Corresponding backend handler node
+	 *  - name[in] - Key in string format
+	 *  - value[in] - Binary value
+	 *  - val_len[in] - Length of value in bytes.
 	 */
 
 	int (*csi_save_end)(struct settings_store *cs);
 	/**< Handler called after an export operation.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node
+	 *  - cs[in] - Corresponding backend handler node
 	 */
 
 	/**< Get pointer to the storage instance used by the backend.
 	 *
 	 * Parameters:
-	 *  - cs - Corresponding backend handler node
+	 *  - cs[in] - Corresponding backend handler node
 	 */
 	void *(*csi_storage_get)(struct settings_store *cs);
 };

subsys/settings/include/settings/settings_zms.h

@@ -20,7 +20,7 @@ extern "C" {
  * The ZMS entry ID for the setting's value is determined implicitly based on
  * the ID of the ZMS entry for the setting's name, once that is found. The
  * difference between name and value ID is constant and equal to
- * ZMS_NAME_ID_OFFSET.
+ * ZMS_DATA_ID_OFFSET.
  *
  * Setting's name is hashed into 29 bits minus hash_collisions_bits.
  * The 2 MSB_bits have always the same value 10, the LL_bit for the name's hash is 0
@@ -68,6 +68,9 @@ extern "C" {
 	((x & ~ZMS_COLLISIONS_MASK) | ((y << 1) & ZMS_COLLISIONS_MASK))
 #define ZMS_COLLISION_NUM(x)     ((x & ZMS_COLLISIONS_MASK) >> 1)
 #define ZMS_NAME_ID_FROM_HASH(x) ((x & ZMS_HASH_TOTAL_MASK) | BIT(31))
+#define ZMS_DATA_ID_FROM_HASH(x) (ZMS_NAME_ID_FROM_HASH(x) + ZMS_DATA_ID_OFFSET)
+#define ZMS_DATA_ID_FROM_NAME(x) (x + ZMS_DATA_ID_OFFSET)
+#define ZMS_DATA_ID_FROM_LL_NODE(x) (ZMS_NAME_ID_FROM_LL_NODE(x) + ZMS_DATA_ID_OFFSET)
 
 struct settings_hash_linked_list {
 	uint32_t previous_hash;