If the nand chip provides us the ECC info, we can use it firstly.
The set_geometry_by_ecc_info() will use the ECC info, and
calculate the parameters we need.

Rename the old code to legacy_set_geometry() which will takes effect
when there is no ECC info from the nand chip or we fails in the ECC info case.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Add the ecc info for TC58NVG2S0F, TC58NVG3S0F, TC58NVG5D2 and TC58NVG6D2.

From these chips' datasheets, we know that:
   The TC58NVG2S0F and TC58NVG3S0F require 4bit ECC for per 512byte.
   The TC58NVG5D2 and TC58NVG6D2 require 40bits ECC for per 1024byte.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Parse out the ECC information for the full-id nand chips.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.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: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The current code uses the hardcode to detect the 16-bit bus width.
Use the onfi_feature() to replace it.

Signed-off-by: Huang Shijie <b32955@freescale.com>
[Brian: small fixup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: David 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 implement the reading of the Extended Parameter Page, and parses
the sections for ECC type, and get the ECC info from the ECC section.

Tested this patch with Micron MT29F64G08CBABAWP.

Acked-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Huang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

add a helper to get the supported features for ONFI nand.
Also add the neccessary macros.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David 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: Pekon Gupta <pekon@ti.com>
Signed-off-by: Huang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: Brian Norris <computersforpeace@gmail.com>
[Brian: amended for checkpatch.pl]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

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

From the ONFI spec, we can just get the ECC info from the @ecc_bits field of
the parameter page.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David 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: Huang Shijie <b32955@freescale.com>
Reviewed-and-tested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

It is better to do the sanity check for the parameter before any hardware
operation.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use NAND_CI_CELLTYPE_MSK to extract the cell type from nand_chip.cellinfo
instead of hardcoded constant.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Acked-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This patch fix following warning:

drivers/mtd/nand/atmel_nand.c:2007: warning: 'atmel_nand_nfc_match' defined but not used

This patch add '#if defined(CONFIG_OF)' block to guard around the definition
of atmel_nand_nfc_match, in order to avoid the warning when the kernel is
configured without DT support.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_write() and mtdtest_erase_eraseblock() in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Iwo Mergler <Iwo.Mergler@netcommwireless.com.au>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_scan_for_bad_eraseblocks() and mtdtest_erase_good_eraseblocks()
in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_scan_for_bad_eraseblocks() and mtdtest_erase_good_eraseblocks()
in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_read(), mtdtest_write(), mtdtest_erase_eraseblock(), and
mtdtest_scan_for_bad_eraseblocks() in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_write(), mtdtest_read(), mtdtest_scan_for_bad_eraseblocks(),
mtdtest_erase_good_eraseblocks() in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_read() and mtdtest_scan_for_bad_eraseblocks() in mtd_test
helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_write(), mtdtest_read(), mtdtest_erase_eraseblock(),
mtdtest_scan_for_bad_eraseblocks(), and mtdtest_erase_good_eraseblocks()
in mtd_test helpers.

[dwmw2: merge later 'remove always true condition' fix]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Use mtdtest_scan_for_bad_eraseblocks(), mtdtest_erase_good_eraseblocks(),
and mtdtest_erase_eraseblock() in mtd_test helpers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Each mtd test module have a single source whose name is the same as
the module name.  In order to link a single object including helper
functions to every test module, this rename these sources to the
different names.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This introduces the helper functions which can be used by several
mtd/tests modules.

The following three functions are used all over the test modules.

- mtdtest_erase_eraseblock()
- mtdtest_scan_for_bad_eraseblocks()
- mtdtest_erase_good_eraseblocks()

The following are wrapper functions for mtd_read() and mtd_write()
which can simplify the return value check.

- mtdtest_read()
- mtdtest_write()

All helpers are put into a single .c file and it will be linked to
every test module later.  The code will actually be copied to every
test module, but it is fine for our small test infrastructure.

[dwmw2: merge later 'return -EIO when mtdtest_read() failed' fix]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

NAND_BBT_SCANEMPTY is a strange, badly-supported option with omap as its
single remaining user.

NAND_BBT_SCANEMPTY was likely used by accident in omap2[1]. And anyway,
omap2 doesn't scan the chip for bad blocks (courtesy of
NAND_SKIP_BBTSCAN), and so its use of this option is irrelevant.

This patch drops the NAND_BBT_SCANEMPTY option.

[1] http://lists.infradead.org/pipermail/linux-mtd/2012-July/042902.html



Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David 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: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The chip->block_markbad pointer should really only be responsible for
writing a bad block marker for new bad blocks. It should not take care
of BBT-related functionality, nor should it handle bookkeeping of bad
block stats.

This patch refactors the 3 users of the block_markbad interface (plus
the default nand_base implementation) so that the common code is kept in
nand_block_markbad_lowlevel(). It removes some inconsistencies between
the various implementations and should allow for more centralized
improvements in the future.

Because gpmi-nand no longer needs the nand_update_bbt() function, let's
stop exporting it as well.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com> (for gpmi-nand parts)
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Just make 'res' an int.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The parent commit 771c568b

 ("mtd: nand: add
accessors, macros for in-memory BBT") makes the following comment obsolete:

	/*
	 * Note that numblocks is 2 * (real numblocks) here, see i+=2
	 * below as it makes shifting and masking less painful
	 */

I don't think it ever could have been "less painful" to have to shift an
extra bit (or 2, or 3) at various points in nand_bbt.c (and even
outside, since we leak our in-memory format). But now it is certainly
more painful, since we have nice macros and functions to retrieve the
relevant portions of the BBT.

This patch removes any points where the block number is
doubled/halved/otherwise-shifted, instead representing the block number
in its most natural form: as the actual block number.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

There is an abundance of magic numbers and complicated shifting/masking
logic in the in-memory BBT code which makes the code unnecessary complex
and hard to read.

This patch adds macros to represent the 00b, 01b, 10b, and 11b
memory-BBT magic numbers, as well as two accessor functions for reading
and marking the memory-BBT bitfield for a given block.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

In case that the nand device will support some features like Nand Flash
Controller, we want to make the sub feature as a sub node of nand device.

Use such organization it is easy to enable/disable feature, also it is back
compatible and more readable.

If the sub-node has a compatible property then it is a driver not partition.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
[ added a missing newline -Brian ]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This patch enable writing nand flash via NFC SRAM. It will minimize the CPU
overhead. The SRAM write only support ECC_NONE and ECC_HW with PMECC.

To enable this NFC write by SRAM feature, you can add a string in dts under
NFC driver node.

This driver has been tested on SAMA5D3X-EK with JFFS2, YAFFS2, UBIFS and
mtd-utils.

Here is part of mtd_speedtest (writing test) result, compare with non-NFC
writing, it reduces %65 cpu load with loss %12 speed.

- commands use to test:
  # insmod /mnt/mtd_speedtest.ko dev=2 &
  # top -n 30 -d 1 | grep speedtest

- test result:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
mtd_speedtest: testing eraseblock write speed
  509   495 root     D     1164   0%   7% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%   8% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%   5% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock write speed is 5194 KiB/s
mtd_speedtest: testing page write speed
  509   495 root     D     1164   0%  32% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  27% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  25% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  30% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page write speed is 5024 KiB/s

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

NFC has embedded sram which can use to transfer data. This patch enable reading
nand flash via NFC SRAM. It will minimize the CPU overhead.

This driver has been tested on SAMA5D3X-EK with JFFS2, YAFFS2, UBIFS and
mtd-utils.

Here puts the part of mtd_speedtest (read test) result as following:
Compare with non-NFC mtd_speedtest result, reading will reduce %45 cpu load
with increase %80 speed.

- commands use to test:
  # insmod /mnt/mtd_speedtest.ko dev=2 &
  # top -n 30 -d 1 | grep speedtest

- test result:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
mtd_speedtest: testing eraseblock read speed
  509   495 root     D     1164   0%  28% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  25% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  26% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock read speed is 9403 KiB/s
mtd_speedtest: testing page read speed
  509   495 root     R     1164   0%  31% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  57% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  53% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  71% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page read speed is 9258 KiB/s

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Nand Flash Controller (NFC) can handle automatic transfers, sending the
commands and address cycles to the NAND Flash.

To use NFC in this driver, user needs to add NFC child node in nand flash
driver. The NFC child node includes NFC's compatible string and regiters
of the address and size of NFC command registers, NFC registers (embedded
in HSMC) and NFC SRAM.
Also user need to set up the HSMC irq, which use to check whether nfc
command is finish or not.

This driver has been tested on SAMA5D3X-EK board with JFFS2, YAFFS,
UBIFS and mtd-utils.

I put the part of the mtd_speedtest result here for your information.
>From the mtd_speedtest, we can see the NFC will reduce the %50 of cpu load
when writing nand flash. No change when reading.
In the meantime, the speed will be slow about %8.

- commands use to test:
    #insmod /mnt/mtd_speedtest.ko dev=2 &
    #top -n 30 -d 1 | grep speedtest

- test result:

Before the patch:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
  515   495 root     R     1164   0%  93% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  98% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  99% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock write speed is 5768 KiB/s
mtd_speedtest: testing eraseblock read speed
  515   495 root     R     1164   0%  92% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  94% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock read speed is 5932 KiB/s
mtd_speedtest: testing page write speed
  515   495 root     R     1164   0%  94% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  98% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  98% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page write speed is 5770 KiB/s
mtd_speedtest: testing page read speed
  515   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  89% insmod /mnt/mtd_speedtest.ko dev=2
  515   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page read speed is 5910 KiB/s

After the patch:
=================================================
mtd_speedtest: MTD device: 2
mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64
mtd_speedtest: testing eraseblock write speed
  509   495 root     D     1164   0%  49% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  50% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  47% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock write speed is 5370 KiB/s
mtd_speedtest: testing eraseblock read speed
  509   495 root     R     1164   0%  92% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  91% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  95% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: eraseblock read speed is 5715 KiB/s
mtd_speedtest: testing page write speed
  509   495 root     D     1164   0%  48% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  47% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     D     1164   0%  50% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page write speed is 5224 KiB/s
mtd_speedtest: testing page read speed
  509   495 root     R     1164   0%  89% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  94% insmod /mnt/mtd_speedtest.ko dev=2
  509   495 root     R     1164   0%  93% insmod /mnt/mtd_speedtest.ko dev=2
mtd_speedtest: page read speed is 5641 KiB/s

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

this will allow to simply the error and remove path

Cc: linux-mtd@lists.infradead.org
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
[josh.wu@atmel.com: fix checkpatch warnings and rebase to latest mtd git tree]
[josh.wu@atmel.com: replace devm_request_and_ioremap with devm_ioremap_resource]
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

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