Modern MLC (and even SLC?) NAND can experience a large number of
bitflips (beyond the recommended correctability capacity) due to drifts
in the voltage threshold (Vt). These bitflips can cause ECC errors to
occur well within the expected lifetime of the flash. To account for
this, some manufacturers provide a mechanism for shifting the Vt
threshold after a corrupted read.

The generic pattern seems to be that a particular flash has N read retry
modes (where N = 0, traditionally), and after an ECC failure, the host
should reconfigure the flash to use the next available mode, then retry
the read operation. This process repeats until all bitfips can be
corrected or until the host has tried all available retry modes.

This patch adds the infrastructure support for a
vendor-specific/flash-specific callback, used for setting the read-retry
mode (i.e., voltage threshold).

For now, this patch always returns the flash to mode 0 (the default
mode) after a successful read-retry, according to the flowchart found in
Micron's datasheets. This may need to change in the future if it is
determined that eventually, mode 0 is insufficient for the majority of
the flash cells (and so for performance reasons, we should leave the
flash in mode 1, 2, etc.).
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NHuang Shijie <b32955@freescale.com>

Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NHuang Shijie <b32955@freescale.com>

s/strenght/strength/

This field isn't used anywhere, so this rename is safe.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The @cellinfo fields contains unused information, such as write caching,
internal chip numbering, etc. But we only use it to check the SLC or MLC.

This patch tries to make it more clear and simple, renames the @cellinfo
to @bits_per_cell.

In order to avoiding the bisect issue, this patch also does the following
changes:
  (0) add a macro NAND_CI_CELLTYPE_SHIFT to avoid the hardcode.

  (1) add a helper to parse out the cell type : nand_get_bits_per_cell()

  (2) parse out the cell type for extended-ID chips and the full-id nand chips.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add a helper to check if a nand chip is SLC or MLC.
This helper makes the code more readable.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This field is never used, except to print it out.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add an instance of an anonymous struct to store the ECC info for full id
nand chips.
	@ecc.strength_ds: ECC correctability from the datasheet.
	@ecc.step_ds: ECC size required by the @ecc.strength_ds,

These two fields are all from the datasheet.

Also add the necessary macros to make the code simple and clean.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

add a helper to get the supported features for ONFI nand.
Also add the neccessary macros.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Since the ONFI 2.1, the onfi spec adds the Extended Parameter Page
to store the ECC info.

The onfi spec tells us that if the nand chip's recommended ECC codeword
size is not 512 bytes, then the @ecc_bits is 0xff. The host _SHOULD_ then
read the Extended ECC information that is part of the extended parameter
page to retrieve the ECC requirements for this device.

This patch adds
    [1] the neccessary fields for nand_onfi_params{},
    [2] and adds the onfi_ext_ecc_info{} for Extended ECC information,
    [3] adds onfi_ext_section{} for extended sections,
    [4] and adds onfi_ext_param_page{} for the Extended Parameter Page.
Acked-by: NPekon Gupta <pekon@ti.com>
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: NBrian Norris <computersforpeace@gmail.com>
[Brian: amended for checkpatch.pl]
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

1.) Why add the ECC information to the nand_chip{} ?
   Each nand chip has its requirement for the ECC correctability, such as
   "4bit ECC for each 512Byte" or "40bit ECC for each 1024Byte".
   This ECC info is very important to the nand controller, such as gpmi.

   Take the Micron MT29F64G08CBABA for example, its geometry is
   8KiB page size, 744 bytes oob size and it requires 40bit ECC per 1KiB.
   If we do not provide the ECC info to the gpmi nand driver, it has to
   calculate the ECC correctability itself. The gpmi driver will gets the 56bit
   ECC for per 1KiB which is beyond its BCH's 40bit ecc capibility.
   The gpmi will quits in this case. But in actually, the gpmi can supports
   this nand chip if it can get the right ECC info.

2.) about the new fields.
   The @ecc_strength_ds stands for the ecc bits needed within the @ecc_step_ds.
   The two fields should be set from the nand chip's datasheets.

   For example:
	"4bit ECC for each 512Byte" could be:
		@ecc_strength_ds = 4, @ecc_step_ds = 512.
	"40bit ECC for each 1024Byte" could be:
		@ecc_strength_ds = 40, @ecc_step_ds = 1024.

3.) Why do not re-use the @strength and @size in the nand_ecc_ctrl{}?
   The @strength and @size in nand_ecc_ctrl{} is used by the nand controller
   driver, while the @ecc_strength_ds and @ecc_step_ds are get from the datasheet.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

nand_base.c shouldn't have to know the implementation details of
nand_bbt's in-memory BBT. Specifically, nand_base shouldn't perform the
bit masking and shifting to isolate a BBT entry.

Instead, just move some of the BBT code into a new nand_markbad_bbt()
interface. This interface allows external users (i.e., nand_base) to
mark a single block as bad in the BBT. Then nand_bbt will take care of
modifying the in-memory BBT and updating the flash-based BBT (if
applicable).
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Spansion's S34MLx chips support ONFI but not the GET/SET FEATURES calls.
Signed-off-by: NDavid Mosberger <dmosberger@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The oob size of Micron's MT29F64G08CBABAWP is 744 bytes.
So increase the NAND_MAX_OOBSIZE to 744.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This remedies a few problems:

(1) The use of "the" vs. "a" is a little confusing, IMO.

(2) nand_chip.block_bad is used exclusively for checking the OOB bad
    block markers of a NAND. Any BBT functionality is handled in
    nand_bbt.c, so this description should differentiate itself from
    nand_bbt.c.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds support for subpage (partial-page) writes when using
hardware based ECC schemes.
Advantages:
(1) reduces storage overhead when using file-systems like UBIFS, which
store LEB header at page-size granularity.
(2) allows independent subpage writes, thereby increasing NAND storage
efficiency for non-page aligned data.
+ updated cafe_nand and lpc32xx_mlc NAND drivers for change in
chip->write_page interface.
Signed-off-by: NGupta, Pekon <pekon@ti.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Notice that all the flashes belonging to the "legacy ID" class have 512 bytes
NAND page. This means we may simplify the 'LEGACY_ID_NAND()' macro as well as
the NAND ID table a little.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

As time goes on, we begin to meet the situation that we can not get enough
information from some nand chips's id data. Take some Toshiba's nand chips
for example. I have 4 Toshiba's nand chips in my hand:
	TC58NVG2S0F, TC58NVG3S0F, TC58NVG5D2, TC58NVG6D2

When we read these chips' datasheets, we will get the geometry of these chips:
	TC58NVG2S0F : 4096 + 224
	TC58NVG3S0F : 4096 + 232
	TC58NVG5D2  : 8192 + 640
	TC58NVG6D2  : 8192 + 640

But we can not parse out the correct oob size for these chips from the id data.

This patch adds some new fields to the nand_flash_dev{}:
  @id_len: the valid length of the id data. See the comments in
           nand_id_has_period()
  @oobsize: the oob size.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Reviewed-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Introduce a helpful macro for the maximum NAND ID sequence length instead of
using the "8" magic number.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Use 'unsigned int' instead of 'unsigned long' in the NAND chip description data
structure, because 32-bits is more than enough for our purposes. We do not need
64-bits, which is what we end up on 64-bit architectures. We declare many
instances of this data structure, so this should help saving some amount of
memory.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Up until now we identified NAND chips by the 'device ID' part of the full chip
ID array, which is the second full ID array byte. However, the newest flashes
use the same device ID for chips with identical page and eraseblock sizes, but
different OOB sizes. And unfortunately, it is not clear if there is a
"standard" way to fetch the OOB size from chip's full ID array. Here is an
example:

Toshiba TC58NVG2S0F: 0x98, 0xdc, 0x90, 0x26, 0x76, 0x15, 0x01, 0x08
Toshiba TC58NVG3S0F: 0x98, 0xd3, 0x90, 0x26, 0x76, 0x15, 0x02, 0x08

The first one is a 512MiB NAND chip with 4KiB NAND pages, 256KiB eraseblock
size and 224 bytes OOB. The second one is a 1GiB NAND chip with the same page
and eraseblock sizes, but with 232 bytes OOB.

This means that we have to store full ID in our NAND flashes table in order to
distinguish between these 2.

This patch adds the 'id[8]' field to the 'struct nand_flash_dev' structure, and
it makes it to be a part of anonymous union, where the second member is a
structure containing the 'mfr_id' and 'dev_id' bytes. The union makes sure that
'mfr_id' refers the same RAM address as 'id[0]' and 'dev_id' refers the same
RAM address as 'id[1]'. The only motivation for the union is an assumption that
'type->dev_id' is more readable than 'type->id[1]'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Introduce helper macros for defining NAND chips. These macros do not really add
much value in the current code-base. However, we are going to add full ID
support which adds some more complexity to the table, and helper macros become
useful for readability.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The 'id' is a bit confusing name because NAND IDs are multi-byte. Re-name
it to 'dev_id' to make it clear that this is the "device ID" part (the second
byte).

While on it, clean-up the commentary for 'struct nand_flash_dev'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We have this unused macro, let's use it and justify its existence.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

It is unused.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

It is not used anywhere.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We have only one AG-AND driver and it was not touched since 2005. It looks
like AG-AND was not really make it to mass-production and can be considered
a dead technology.

Along with the AG-AND support, this patch removes the BBT_AUTO_REFRESH feature,
because the only user of this feature is AG-AND. And even though it is
implemented as a generic feature, I prefer to remove it because NAND flashes do
not really need it in this form.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This partially reverts commit 1696e6bc
("mtd: nand: kill NAND_NO_READRDY").

In that patch I overlooked a few things.

The original documentation for NAND_NO_READRDY included "True for all
large page devices, as they do not support autoincrement." I was
conflating "not support autoincrement" with the NAND_NO_AUTOINCR option,
which was in fact doing nothing. So, when I dropped NAND_NO_AUTOINCR, I
concluded that I then could harmlessly drop NAND_NO_READRDY. But of
course the fact the NAND_NO_AUTOINCR was doing nothing didn't mean
NAND_NO_READRDY was doing nothing...

So, NAND_NO_READRDY is re-introduced as NAND_NEED_READRDY and applied
only to those few remaining small-page NAND which needed it in the first
place.

Cc: stable@kernel.org [3.5+]
Reported-by: NAlexander Shiyan <shc_work@mail.ru>
Tested-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The driver call nand_scan_ident in 8 bit mode, then
readid or onfi detection are done (and detect bus width).
The driver should update its bus width before calling nand_scan_tail.

This work because readid and onfi are read work 8 byte mode.

Note that nand_scan_ident send command (NAND_CMD_RESET, NAND_CMD_READID, NAND_CMD_PARAM), address and read data
The ONFI specificication is not very clear for x16 device if high byte of address should be driven to 0,
but according to [1] it should be ok to not drive it during autodetection.

[1]
3.3.2. Target Initialization

[...]
The Read ID and Read Parameter Page commands only use the lower 8-bits of the data bus.
The host shall not issue commands that use a word data width on x16 devices until the host
determines the device supports a 16-bit data bus width in the parameter page.
Signed-off-by: NMatthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Add missing colons to fix kernel-doc generation warnings.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Some Hynix and Samsung MLC NAND have 640B OOB size. Sooner or later, we should
dynamically allocate the buffers that use these macros.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

add onfi_get_async_timing_mode() to get the supportted asynchronous
timing mode.

add onfi_get_sync_timing_mode() to get the supportted synchronous
timing mode.

Also add the neccessary macros : the timing modes.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Add the set-features(0xef)/get-features(0xee) helpers for ONFI nand.
Also add the necessary macros.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In the absence of any formal documentation of the nand interface, I thought this
patch to the header file might be helpful.
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Added a NAND device flag for subpage read support. Previously this was
hard coded based on large page and soft ECC.
Updated base NAND driver to use the new subpage read flag if the NAND is
large page and soft ECC.
Signed-off-by: NJeff Westfahl <jeff.westfahl@ni.com>
Reviewed-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fix kernel-doc warning in <linux/mtd/nand.h>:

Warning(include/linux/mtd/nand.h:659): No description found for parameter 'read_byte'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Just as Artem suggested:

"Both UBI and JFFS2 are able to read verify what they wrote already.
There are also MTD tests which do this verification. So I think there
is no reason to keep this in the NAND layer, let alone wasting RAM in
the driver to support this feature. Besides, it does not work for sub-pages
and many drivers have it broken. It hurts more than it provides benefits."

So kill MTD_NAND_VERIFY_WRITE entirely.
Signed-off-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The NAND_CHIPOPTIONS_MSK has limited utility and is causing real bugs. It
silently masks off at least one flag that might be set by the driver
(NAND_NO_SUBPAGE_WRITE). This breaks the GPMI NAND driver and possibly
others.

Really, as long as driver writers exercise a small amount of care with
NAND_* options, this mask is not necessary at all; it was only here to
prevent certain options from accidentally being set by the driver. But the
original thought turns out to be a bad idea occasionally. Thus, kill it.

Note, this patch fixes some major gpmi-nand breakage.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Tested-by: NHuang Shijie <shijie8@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

There is an implemention of hardware ECC write page function which may return an
error indication.
For instance, using Atmel HW PMECC to write one page into a nand flash, the hardware
engine will compute the BCH ecc code for this page. so we need read a the
status register to theck whether the ecc code is generated.
But we cannot assume the status register always can be ready, for example,
incorrect hardware configuration or hardware issue, in such case we need
write_page() to return a error code.

Since the definition of 'write_page' function in struct nand_ecc_ctrl is 'void'.
So this patch will:
  1. add return 'int' value for 'write_page' function.
  2. to be consitent, add return 'int' value for 'write_page_raw' fuctions too.
  3. add code to test the return value, and if negative, indicate an
  error happend when write page with ECC.
  4. fix the compile warning in all impacted nand flash driver.

Note: I couldn't compile-test all of these easily, as some had ARCH dependencies.
Signed-off-by: NJosh Wu <josh.wu@atmel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

According to its documentation, the NAND_NO_READRDY option is always used
when autoincrement is not supported. Autoincrement support was recently
dropped, so we can drop this options as well (defaulting to "no read ready
check").
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>