While the standard NAND OOB functions do not do ECC on the spare area,
it is possible for a driver to supply its own OOB ECC functions (e.g., HW
ECC). nand_do_read_oob should act like nand_do_read_ops in checking the
ECC stats and returning -EBADMSG or -EUCLEAN on uncorrectable errors or
correctable bitflips, respectively. These error codes could be used in
flash-based BBT code or in YAFFS, for example.

Doing this, however, messes with the behavior of mtd_do_readoob. Now,
mtd_do_readoob should check whether we had -EUCLEAN or -EBADMSG errors
and discard those as "non-fatal" so that the ioctls can still succeed
with (possibly uncorrected) data.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Therefor -> Therefore
[Intern], [Internal] -> [INTERN]
[REPLACABLE] -> [REPLACEABLE]
syndrom, syndom -> syndrome
ecc -> ECC
buswith -> buswidth
endianess -> endianness
dont -> don't
occures -> occurs
independend -> independent
wihin -> within
erease -> erase
blockes -> blocks
...
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

In nand_do_write_ops() code it is possible for a caller to provide
ops.oobbuf populated and ops.mode == MTD_OOB_AUTO, which currently
means that the chip->oob_poi buffer isn't initialised to all 0xFF.
The nand_fill_oob() method then carries out the task of copying
the provided OOB data to oob_poi, but with MTD_OOB_AUTO it skips
areas marked as unavailable by the layout struct, including the
bad block marker bytes.

An example of this causing issues is when the last OOB data read
was from the start of a bad block where the markers are not 0xFF,
and the caller wishes to write new OOB data at the beginning of
another block. In this scenario the caller would provide OOB data,
but nand_fill_oob() would skip the bad block marker bytes in
oob_poi before copying the OOB data provided by the caller.
This means that when the OOB data is written back to NAND,
the block is inadvertently marked as bad without the caller knowing.
This has been witnessed when using YAFFS2 where tags are stored
in the OOB.

To avoid this oob_poi is always initialised to 0xFF to make sure
no left over data is inadvertently written back to the OOB area.

Credits to Brian Norris <computersforpeace@gmail.com> for fixing this
patch.
Signed-off-by: NAdam Thomson <adam.thomson@alcatel-lucent.com>
Signed-off-by: NArtem Bityutskiy <dedekind1@gmail.com>
Cc: stable@kernel.org [2.6.20+]

Artem: while on it, do other commentaries clean-ups:
1. Start one-line comments with capital letter and no dot at the end
2. Turn sparse multi-line comments into one-line comments
3. Change "phrase ?" to "phrase?" and the same with "!".
4. Remove tabs from the kerneldoc parameters comments - they are mixed
   with tabs often, and inconsistent.
5. Put dot at the end of descriptions in kerneldoc comments.
6. Some other small commentaries clean-ups
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

I believe this TODO was unnecessary back when it was introduced:
	commit d1e1f4e4
	mtd: nand: add support for reading ONFI parameters...
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This delay is meaningless. If delay is needed it is device specific
and must be reimplemented by specific driver, otherwise no delay is
needed.
Signed-off-by: NJiri Pinkava <jiri.pinkava@vscht.cz>
Acked-by: NVimal Singh <vimal.newwork@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Recall the recently added prefix requirements:
 * "NAND_" for flags in nand.h, used in nand_chip.options
 * "NAND_BBT_" for flags in bbm.h, used in nand_chip.bbt_options
        or in nand_bbt_descr.options

Thus, I am changing NAND_USE_FLASH_BBT to NAND_BBT_USE_FLASH.

Again, this flag is found in bbm.h and so should NOT be used in the
"nand_chip.options" field.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch works with the following three flags from two headers (nand.h
and bbm.h):
  (1) NAND_USE_FLASH_BBT (nand.h)
  (2) NAND_USE_FLASH_BBT_NO_OOB (nand.h)
  (3) NAND_BBT_NO_OOB (bbm.h)

These flags are all related and interdependent, yet they were in
different headers. Flag (2) is simply the combination of (1) and (3) and
can be eliminated.

This patch accomplishes the following:
  * eliminate NAND_USE_FLASH_BBT_NO_OOB (i.e., flag (2))
  * move NAND_USE_FLASH_BBT (i.e., flag (1)) to bbm.h

It's important to note that because (1) and (3) are now both found in
bbm.h, they should NOT be used in the "nand_chip.options" field.

I removed a small section from the mtdnand DocBook because it referes to
NAND_USE_FLASH_BBT in nand.h, which has been moved to bbm.h.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch handles the problems we've been having with using conflicting
flags from nand.h and bbm.h in the same nand_chip.options field. We
should try to separate these two spaces a little more clearly, and so I
have added a bbt_options field to nand_chip.

Important notes about nand_chip fields:
* bbt_options field should contain ONLY flags from bbm.h. They should be
  able to pass safely to a nand_bbt_descr data structure.
    - BBT option flags start with the "NAND_BBT_" prefix.
* options field should contian ONLY flags from nand.h. Ideally, they
  should not be involved in any BBT related options.
    - NAND chip option flags start with the "NAND_" prefix.
* Every flag should have a nice comment explaining what the flag is. While
  this is not yet the case on all existing flags, please be sure to write
  one for new flags. Even better, you can help document the code better
  yourself!

Please try to follow these conventions to make everyone's lives easier.

Among the flags that are being moved to the new bbt_options field
throughout various drivers, etc. are:
 * NAND_BBT_SCANLASTPAGE
 * NAND_BBT_SCAN2NDPAGE
and there will be more to come.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch reverts most of:
    commit 58373ff0
    mtd: nand: more BB Detection refactoring and dynamic scan options

According to the discussion at:
    http://lists.infradead.org/pipermail/linux-mtd/2011-May/035696.html
the NAND_BBT_SCANBYTE1AND6 flag, although technically valid, can break
some existing ECC layouts that use the 6th byte in the OOB for ECC data.
Furthermore, we apparently do not need to scan both bytes 1 and 6 in
the OOB region of the devices under consideration; instead, we only need
to scan one or the other.

Thus, the NAND_BBT_SCANBYTE1AND6 flag is at best unnecessary and at
worst a regression.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Convert to mtd_device_register() and remove the CONFIG_MTD_PARTITIONS
preprocessor conditionals as partitioning is always available.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In commit c7b28e25 the initialization of
the backblockbits was accidentally removed. This patch returns it back,
because otherwise some NAND drivers are broken.

This problem was reported by "Saxena, Parth <parth.saxena@ti.com>" here:
http://lists.infradead.org/pipermail/linux-mtd/2011-April/035221.htmlReported-by: NSaxena, Parth <parth.saxena@ti.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Tested-by: NSaxena, Parth <parth.saxena@ti.com>
Acked-by: NSaxena, Parth <parth.saxena@ti.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Cc: stable@kernel.org [2.6.36+]
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Chip deselection is already done in nand_release_device. So only
duplicate code.
Signed-off-by: NJiri Pinkava <jiri.pinkava@vscht.cz>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

This patch adds software BCH ECC support to mtd, in order to handle recent
NAND device ecc requirements (4 bits or more).

It does so by adding a new ecc mode (NAND_ECC_SOFT_BCH) for use by board
drivers, and a new Kconfig option to enable BCH support. It relies on the
generic BCH library introduced in a previous patch.

When a board driver uses mode NAND_ECC_SOFT_BCH, it should also set fields
chip->ecc.size and chip->ecc.bytes to select BCH ecc data size and required
error correction capability. See nand_bch_init() documentation for details.

It has been tested on the following platforms using mtd-utils, UBI and
UBIFS: x86 (with nandsim), arm926ejs.
Signed-off-by: NIvan Djelic <ivan.djelic@parrot.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NJason Liu <r64343@freescale.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Initialize mtd->writebufsize to be equal to mtd->writesize.
Signed-off-by: NAnatolij Gustschin <agust@denx.de>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In checking for the ONFI revision, the first conditional (for checking
"unsupported" ONFI) seems unnecessary.  All ONFI revisions should be
backwards-compatible; even if this is not the case on some newer ONFI
revision, it should simply fail the second version-checking if-else block
(i.e., the bit-fields for 1.0, 2.0, etc. would not be set to 1). Thus, we
move our "unsupported" condition after having checked each bit field.

Also, it's simple enough to add a condition for ONFI revision 2.3. Note
that this does *NOT* mean we handle all new features of ONFI versions
above 1.0.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We have the order of the conditional wrong for choosing the ONFI chip name
vs. the ID table name. Without this fix, we will almost *always* choose a
NULL string to print out instead of the correct one.

This has already been suggested by Matthieu Castet.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This reverts commit e14feafb.

The commit limits the maximum amount of bytes which can be read
at one go to the OOB size, which is incorrect, because mtd->read_oob()
allows reading multiple pages at a time, see comment near
"struct mtd_oob_ops" at include/linux/mtd/mtd.h. So this patch
breaks ABI and hence, has to be reverted.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

When run mtd_oobtest case, there will be one error for step(4),
which turned out it need add one check for out of page read in
nand_do_read_oob just like mtd_do_write_oob did it already.
This commit also fix one typo error for comments in mtd_do_write_oob
Signed-off-by: NJason Liu <r64343@freescale.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

RAW writes were broken by 782ce79a
which introduced a check of ops->ooboffs in nand_do_write_ops().

When writing in RAW mode this is called with an ops struct on the stack
of mtdchar.c:mtd_write() which does not initialise ops->ooboffs, so it
is garbage and fails this test.

This test does not make sense if ops->oobbuf is NULL, which it is in the
RAW write path, so include that in the test.
Signed-off-by: NJon Povey <jon.povey@racelogic.co.uk>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Not all the NAND devices have all the information in additional
id bytes.

So add a hook in the nand_chip{} is a good method to calculate the
right value of oobsize, erasesize and so on.

Without the hook,you will get the wrong value, and you have to hack
in the ->scan_bbt() to change the wrong value which make the code
mess.
Signed-off-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Currently MTD caches the last read NAND page, even if there was an uncorrectable ECC
error. This patch prevents caching in case of uncorrectable ECC errors. The reason
is that we want to allow the user to re-read the NAND page several times. In case of
unstable bits re-trying may help.

Moreover, current behavior is wrong because the first read returns -EBADMSG (correctly)
but the second read succeeds and incorrectly returns 0 (because we read from the cache).
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Only 3 warnings are left, one is off by one character, but splitting the line
would reduce the readability. One is for a for loop statement, which would also
not improve readability. The last one is a false positive on a test.

Artem: it is much easier to verify patches against nand_base.c with
       checkpatch.pl when nand_base.c itself does not have so many
       checkpatch.pl warnings.
Signed-off-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Artem: it is much easier to verify patches against nand_base.c with
       checkpatch.pl when nand_base.c itself does not have so many
       checkpatch.pl warnings.
Signed-off-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In order to reduce the indentation and improve the readability of nand_get_
flash_type, split the ONFI detection logic to its own function. The detection
logic inside nand_flash_detect_onfi is also rewritten to allow for less
indentation.
Signed-off-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds support for reading NAND device ONFI parameters and use
the ONFI informations to define its geometry. In case the device supports
ONFI, the onfi_version field in struct nand_chip contains the version (BCD)
and the onfi_params structure can be used by drivers to set up timings and
such. We currently only support ONFI 1.0 parameters.
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NMatthieu Castet <matthieu.castet@parrot.com>
Signed-off-by: NMaxime Bizon <mbizon@freebox.fr>
Signed-off-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

There are some additions to the detection scheme used by Samsung
MLC NAND. These simple changes to support the 400- and 436-byte OOB
are found in the following data sheet:

Samsung K9GBG08U0M (p.40)
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Toshiba does not use ONFI for their NAND flash. So we have to continue
to add new IDs used by Toshiba devices as well as heuristic detection
for scanning the 2nd page for a BBM. This is a relatively harmless
start at supporting many of them.

These chips mostly follow the same ID fields of previous generations,
but there is a need for a tweak.

These chips introduce a strange 576 byte OOB (that's 36 bytes per
512 bytes of page). In the preliminary data, Toshiba has not
defined exactly how their ID strings should decode. In the future,
a new tweak must be added.

Data is taken from, among others, Toshiba TC58TxG4S2FBAxx
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Some Spansion chips have a method for determining eraseblock size that
is incompatible with similar ID chips of other sizes. This implements
some heuristic detection of these differences.

This patch checks for a 5-byte ID with trailing zeros as well as a
512-byte page size to ensure that chips are not misdetected as the
S30MLxxxP ORNAND series.

[Tweaked by Artem a bit]
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Drivers may (and do) return negative errno values other than -1 from the
ecc.correct callback.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Apparently, the check for a 6-byte ID string introduced by commit
426c457a ("mtd: nand: extend NAND flash
detection to new MLC chips") is NOT sufficient to determine whether or
not a Samsung chip uses their new MLC detection scheme or the old,
standard scheme. This adds a condition to check cell type.
Signed-off-by: NTilman Sauerbeck <tilman@code-monkey.de>
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org

Commit c7b28e25 ("mtd: nand: refactor BB 
marker detection") caused a regression in detection of factory-set bad 
block markers, especially for certain small-page NAND. This fix removes 
some unneeded constraints on using NAND_SMALL_BADBLOCK_POS, making the 
detection code more correct.

This regression can be seen, for example, in Hynix HY27US081G1M and
similar.
Signed-off-by: NBrian Norris <norris@broadcom.com>
Tested-by: NMichael Guntsche <mike@it-loops.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fix mtd/nand_base.c kernel-doc warnings and typos.

Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix mtd/nand_base.c kernel-doc warnings and typos.

Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This is an update that depends on the previous patches I sent.

We can now write to all the appropriate BB marker locations (i.e.
pages 1 AND 2, bytes 1 AND 6) with nand_default_block_markbad() if
necessary, according to the flags marked in chip->options.

Note that I removed the line:
	ofs += mtd->oobsize;
Unless I am wrong, this line was completely unnecessary in the
first place.
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>