Since in SAMA5D4 chip, the PMECC can correct bit flips in erased page.
So we add a DT property to indicate this hardware character.

If the PMECC support correct bitflip erased page (all data are 0xff).
Then we can use the PMECC correct the page and skip the erased page
check.
Signed-off-by: NJosh Wu <josh.wu@atmel.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

If there is no PMECC lookup table stored in ROM, or lookup table offset is
not specified, PMECC driver should build it in DDR by itself.

That make the PMECC driver work for some board which doesn't have PMECC
lookup table in ROM.

The PMECC use the BCH algorithm, so based on the build_gf_tables()
function in lib/bch.c, we can build the Galois Field lookup table.

For more information can refer to section 5.4 of PMECC controller
application note:
	http://www.atmel.com/images/doc11127.pdfSigned-off-by: NJosh Wu <josh.wu@atmel.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Retrieve the NFC clock to make sure it is enabled. Make that optional to ensure
compatibility with previous device trees but document it as mandatory so newer
device trees will include it.
Signed-off-by: NBoris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: NJosh Wu <josh.wu@atmel.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.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: NJosh Wu <josh.wu@atmel.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid 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: 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>

This patch will set the nand dma support in dts. Since we will not use
cpu_is_xxx() in nand driver. We needn't include the mach/cpu.h any more.
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>

Add DT support for PMECC parameters.
Signed-off-by: NHong Xu <hong.xu@atmel.com>
Signed-off-by: NJosh Wu <josh.wu@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Add comments to NAND "gpios" property to make it clearer.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

Use a local copy of board informatin and fill with DT data.
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>