fs/littlefs: add LFS_MULTIVERSION support

fs/littlefs/CMakeLists.txt

@@ -59,7 +59,8 @@ if(CONFIG_FS_LITTLEFS)
             -DLFS_CONFIG=${CMAKE_CURRENT_LIST_DIR}/lfs_vfs.h
             -DLFS_NAME_MAX=${CONFIG_FS_LITTLEFS_NAME_MAX}
             -DLFS_FILE_MAX=${CONFIG_FS_LITTLEFS_FILE_MAX}
-            -DLFS_ATTR_MAX=${CONFIG_FS_LITTLEFS_ATTR_MAX})
+            -DLFS_ATTR_MAX=${CONFIG_FS_LITTLEFS_ATTR_MAX}
+            $<$<BOOL:${CONFIG_FS_LITTLEFS_MULTI_VERSION}>:-DLFS_MULTIVERSION>)
 
   # Note: the littlefs upstream doesn't seems to care -Wshadow cf.
   # https://github.com/littlefs-project/littlefs/pull/873

fs/littlefs/Kconfig

@@ -158,4 +158,21 @@ config FS_LITTLEFS_VERSION
 	---help---
 		The LITTLEFS version to use.
 
+config FS_LITTLEFS_MULTI_VERSION
+	bool "Support multiple on-disk versions"
+	default n
+	---help---
+		Enable LFS_MULTIVERSION for LITTLEFS file system
+
+config FS_LITTLEFS_DISK_VERSION
+	hex "LITTLEFS on-disk version"
+	default 0x0
+	depends on FS_LITTLEFS_MULTI_VERSION
+	---help---
+		The LITTLEFS disk version to use.
+
+		0 means to leave it to the default from the LITTLEFS.
+		0x00020000 means 2.0.
+		0x00020001 means 2.1.
+
 endif

fs/littlefs/Make.defs

@@ -50,6 +50,9 @@ CFLAGS += -DLFS_CONFIG=../lfs_vfs.h
 CFLAGS += -DLFS_NAME_MAX=$(CONFIG_FS_LITTLEFS_NAME_MAX)
 CFLAGS += -DLFS_FILE_MAX=$(CONFIG_FS_LITTLEFS_FILE_MAX)
 CFLAGS += -DLFS_ATTR_MAX=$(CONFIG_FS_LITTLEFS_ATTR_MAX)
+ifeq ($(CONFIG_FS_LITTLEFS_MULTI_VERSION),y)
+CFLAGS += -DLFS_MULTIVERSION
+endif
 
 LITTLEFS_TARBALL = $(CONFIG_FS_LITTLEFS_VERSION).tar.gz
 

fs/littlefs/lfs_vfs.c

@@ -1323,6 +1323,10 @@ static int littlefs_bind(FAR struct inode *driver, FAR const void *data,
   fs->cfg.lookahead_size = CONFIG_FS_LITTLEFS_LOOKAHEAD_SIZE;
 #endif
 
+#ifdef CONFIG_FS_LITTLEFS_MULTI_VERSION
+  fs->cfg.disk_version   = CONFIG_FS_LITTLEFS_DISK_VERSION;
+#endif
+
   /* Then get information about the littlefs filesystem on the devices
    * managed by this driver.
    */