Bluetooth: Mesh: Add key-value concept to store model data

Previous mode store function only can store single data,
change this to store as KV model, let's app-layer to manager
model data, other than by stack when node reset.

Signed-off-by: Lingao Meng <mengabc1086@gmail.com>

include/bluetooth/mesh/access.h

@@ -460,6 +460,7 @@ struct bt_mesh_model_cb {
 	 *  @sa settings_handler::h_set
 	 *
 	 *  @param model   Model to set the persistent data of.
+	 *  @param name    Name/key of the settings item.
 	 *  @param len_rd  The size of the data found in the backend.
 	 *  @param read_cb Function provided to read the data from the backend.
 	 *  @param cb_arg  Arguments for the read function provided by the
@@ -468,8 +469,8 @@ struct bt_mesh_model_cb {
 	 *  @return 0 on success, error otherwise.
 	 */
 	int (*const settings_set)(struct bt_mesh_model *model,
-				  size_t len_rd, settings_read_cb read_cb,
+				  const char *name, size_t len_rd,
-				  void *cb_arg);
+				  settings_read_cb read_cb, void *cb_arg);
 
 	/** @brief Callback called when the mesh is started.
 	 *
@@ -504,6 +505,9 @@ struct bt_mesh_model_cb {
 	 *  Called when the mesh node is reset. All model data is deleted on
 	 *  reset, and the model should clear its state.
 	 *
+	 *  @note If the model stores any persistent data, this needs to be
+	 *  erased manually.
+	 *
 	 *  @param model Model this callback belongs to.
 	 */
 	void (*const reset)(struct bt_mesh_model *model);
@@ -662,13 +666,15 @@ static inline bool bt_mesh_model_in_primary(const struct bt_mesh_model *mod)
  *
  *  @param mod      Mesh model.
  *  @param vnd      This is a vendor model.
+ *  @param name     Name/key of the settings item.
  *  @param data     Model data to store, or NULL to delete any model data.
  *  @param data_len Length of the model data.
  *
  *  @return 0 on success, or (negative) error code on failure.
  */
 int bt_mesh_model_data_store(struct bt_mesh_model *mod, bool vnd,
-			     const void *data, size_t data_len);
+			 const char *name, const void *data,
+			 size_t data_len);
 
 /** @brief Let a model extend another.
  *

subsys/bluetooth/mesh/access.h

@@ -11,8 +11,7 @@ enum {
 	BT_MESH_MOD_BIND_PENDING = BIT(0),
 	BT_MESH_MOD_SUB_PENDING = BIT(1),
 	BT_MESH_MOD_PUB_PENDING = BIT(2),
-	BT_MESH_MOD_DATA_PRESENT = BIT(3),
+	BT_MESH_MOD_NEXT_IS_PARENT = BIT(3),
-	BT_MESH_MOD_NEXT_IS_PARENT = BIT(4),
 };
 
 /* Tree walk return codes */

subsys/bluetooth/mesh/cfg_srv.c

@@ -3311,8 +3311,6 @@ static void mod_reset(struct bt_mesh_model *mod, struct bt_mesh_elem *elem,
 		if (clear_count) {
 			bt_mesh_store_mod_sub(mod);
 		}
-
-		bt_mesh_model_data_store(mod, vnd, NULL, 0);
 	}
 
 	if (mod->cb && mod->cb->reset) {

subsys/bluetooth/mesh/settings.c

@@ -652,6 +652,22 @@ static int mod_set_pub(struct bt_mesh_model *mod, size_t len_rd,
 	return 0;
 }
 
+static int mod_data_set(struct bt_mesh_model *mod,
+			const char *name, size_t len_rd,
+			settings_read_cb read_cb, void *cb_arg)
+{
+	const char *next;
+
+	settings_name_next(name, &next);
+
+	if (mod->cb && mod->cb->settings_set) {
+		return mod->cb->settings_set(mod, next, len_rd,
+			read_cb, cb_arg);
+	}
+
+	return 0;
+}
+
 static int mod_set(bool vnd, const char *name, size_t len_rd,
 		   settings_read_cb read_cb, void *cb_arg)
 {
@@ -700,11 +716,7 @@ static int mod_set(bool vnd, const char *name, size_t len_rd,
 	}
 
 	if (!strncmp(next, "data", len)) {
-		mod->flags |= BT_MESH_MOD_DATA_PRESENT;
+		return mod_data_set(mod, next, len_rd, read_cb, cb_arg);
-
-		if (mod->cb && mod->cb->settings_set) {
-			return mod->cb->settings_set(mod, len_rd, read_cb, cb_arg);
-		}
 	}
 
 	BT_WARN("Unknown module key %s", next);
@@ -2436,22 +2448,22 @@ void bt_mesh_clear_cdb_app_key(struct bt_mesh_cdb_app_key *key)
 }
 
 int bt_mesh_model_data_store(struct bt_mesh_model *mod, bool vnd,
-			     const void *data, size_t data_len)
+			const char *name, const void *data,
+			size_t data_len)
 {
-	char path[20];
+	char path[30];
 	int err;
 
 	encode_mod_path(mod, vnd, "data", path, sizeof(path));
+	if (name) {
+		strcat(path, "/");
+		strncat(path, name, 8);
+	}
 
 	if (data_len) {
-		mod->flags |= BT_MESH_MOD_DATA_PRESENT;
 		err = settings_save_one(path, data, data_len);
-	} else if (mod->flags & BT_MESH_MOD_DATA_PRESENT) {
-		mod->flags &= ~BT_MESH_MOD_DATA_PRESENT;
-		err = settings_delete(path);
 	} else {
-		/* Nothing to delete */
+		err = settings_delete(path);
-		err = 0;
 	}
 
 	if (err) {