[JFFS2] Add support for JFFS2-on-Dataflash devices.

For Dataflash, can_mark_obsolete = false and the NAND write buffering
code (wbuf.c) is used.

Since the DataFlash chip will automatically erase pages when writing,
the cleanmarkers are not needed - so cleanmarker_oob = false and
cleanmarker_size = 0

DataFlash page-sizes are not a power of two (they're multiples of 528
bytes).  The SECTOR_ADDR macro (added in the previous core patch) is
replaced with a (slower) div/mod version if CONFIG_JFFS2_FS_DATAFLASH is
selected.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 6a4ad4bb7a54..07835d24c785 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1084,6 +1084,13 @@ config JFFS2_FS_NOR_ECC
           ECC for JFFS2. This type of flash chip is not common, however it is
           available from ST Microelectronics.
 
+config JFFS2_FS_DATAFLASH
+        bool "JFFS2 support for DataFlash (EXPERIMENTAL)"
+        depends on JFFS2_FS && EXPERIMENTAL
+        default n
+        help
+          This enables the experimental support for JFFS2 on DataFlash devices.
+
 config JFFS2_COMPRESSION_OPTIONS
         bool "Advanced compression options for JFFS2"
         depends on JFFS2_FS