What is OTP in OneNAND?
The device includes,
1. one block-sized OTP (One Time Programmable) area and
2. user-controlled 1st block OTP(Block 0)
that can be used to increase system security or to provide
identification capabilities.

What is done?
In OneNAND, one block of the NAND Array is set aside as an OTP
memory area, and 1st Block (Block 0) can be used as OTP area.
This area, available to the user, can be configured and locked
with secured user information. The OTP block can be read,
programmed and locked using the same operations as any other NAND
Flash Array memory block. After issuing an OTP-Lock, OTP block
cannot be erased. OTP block is fully-guaranteed to be a good
block.

Why it is done?
Locking the 1st Block OTP has the effect of a 'Write-protect' to
guard against accidental re-programming of data stored in the 1st
block and OTP Block.

Which problem it solves?
OTP support is provided in the existing implementation of
OneNAND/Flex-OneNAND driver, but it is not working with OneNAND
devices. Have observed the following in current OTP OneNAND Implmentation,
1. DataSheet specific sequence to lock the OTP Area is not followed.
2. Certain functions are quiet generic to cope with OTP specific activity.
This patch re-implements OTP support for OneNAND device.

How it is done?
For all blocks, 8th word is available to the user.
However, in case of OTP Block, 8th word of sector 0, page 0 is reserved as
OTP Locking Bit area. Therefore, in case of OTP Block, user usage on this
area is prohibited. Condition specific values are entered in the 8th word,
sector0, page 0 of the OTP block during the process of issuing an OTP-Lock.
The possible conditions are:
1. Only 1st Block Lock
2. Only OTP Block Lock
3. Lock both the 1st Block and the OTP Block

What Other feature additions have been done in this patch?
This patch adds feature for:
1. Only 1st Block Lock
2. Lock both the 1st Block and the OTP Blocks

Re-implemented OTP support for OneNAND
Added following features to OneNAND
	1. Lock only 1st Block in OneNAND
	2. Lock BOTH 1st Block and OTP Block in OneNAND

[comments were slightly tweaked by Artem]

Signed-off-by: Amul Kumar Saha <amul.saha@samsung.com>
Reviewed-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

nand.h, onenand.h and flashchip.h defined enumeration types
for chip status using the same symbolic names. This prevented
a board file to include more than one of them. In particular,
no nand and onenand platform devices could live in the same file.
This patch augments flashchip.h with a few status values in order
to cover all cases, so nand.h and onenand.h can use flstate_t
without declaring their own status enum.

Signed-off-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Remove the ARM dependency from the generic "onenand" platform device
driver.  This change makes the driver useful for other architectures as
well.  Needed for the SuperH kfr2r09 board.

Apart from the obvious Kconfig bits, the most important change is the move
away from ARM specific includes and platform data.  Together with this
change the only in-tree board code gets an update, and the driver name is
also changed gracefully break potential out of tree drivers.

The driver is also updated to allow NULL as platform data together with a
few changes to make use of resource_size() and dev_name().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Kyungmin Park <kmpark@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Add bbt_wait & unlock_all as replaceable for some platform such as
  s3c64xx s3c64xx has its own OneNAND controller and another interface

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Add support for Samsung Flex-OneNAND devices.

Flex-OneNAND combines SLC and MLC technologies into a single device.
SLC area provides increased reliability and speed, suitable for storing
code such as bootloader, kernel and root file system.  MLC area
provides high density and is suitable for storing user data.

SLC and MLC regions can be configured through kernel parameter.

[akpm@linux-foundation.org: export flexoand_region and onenand_addr]
Signed-off-by: Rohit Hagargundgi <h.rohit@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Vishak G <vishak.g@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

In addition to adding the Numonyx manufacturer code, this patch
also ensures 'sync. write' is disabled when reading identification
data - something that the Numonyx chip objects to, but the
Samsung chip seems to ignore.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This patch adds a proper prototype for onenand_bbt_read_oob() in
include/linux/mtd/onenand.h

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

The 2X Program is an extension of Program Operation.

Since the device is equipped with two DataRAMs, and two-plane NAND Flash 
memory array, these two component enables simultaneous program of 4KiB.
Plane1 has only even blocks such as block0, block2, block4 while Plane2 
has only odd blocks such as block1, block3, block5.
So MTD regards it as 4KiB page size and 256KiB block size

Now the following chips support it. (KFXXX16Q2M)
Demux: KFG2G16Q2M, KFH4G16Q2M, KFW8G16Q2M,
Mux:   KFM2G16Q2M, KFN4G16Q2M,

And more recent chips

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Classify the page data and oob buffer
and it prevents the memory fragementation (writesize + oobsize)

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

It use blockpage instead of a pair (block, page). It can also cover a small chunk access. 0x00, 0x20, 0x40 and so on.

And in JFFS2 behavior, sometimes it reads two pages alternatively.
e.g., It first reads A page, B page and A page.
So we check another bufferram to find requested page.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>