Introduction of the MTD pairing scheme concept.

Introduced by commit fde85cfd ("mtd: nand: Fix nand_command_lp() for
8bits opcodes") and I didn't have the heart to have Boris rewrite his
pull request just for that. Anyway, there's some value in having stable
commit hashes.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

"
Notable core changes:
- add the infrastructure to automate NAND timings configuration
- provide a generic DT property to maximize ECC strength

The rest is just a bunch of minor drivers and core fixes/cleanup
patches.
"

Also not noted: some refactoring in the core bad block table handling,
to help with improving some of the logic in error cases.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

If the master device has callbacks for _get/put_device()
and this MTD has slaves a get_mtd_device() call on paritions
will never issue the registered callbacks.
Fix this by propagating _get/put_device() down.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Provide a nand_cleanup() function to free all nand related resources
without unregistering the mtd device.
This should allow drivers to call mtd_device_unregister() and handle
its return value and still being able to cleanup all nand related
resources.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Daniel Walter <dwalter@sigma-star.at>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Commit d48f62b9 ("mtd: nand: move of_get_nand_xxx() helpers into
nand_base.c") removed the drivers/of/of_mtd.c file but did not remove
the associated OF_MTD Kconfig option.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

We are about to drop the OF_MTD Kconfig option. Test CONFIG_OF
activation instead of CONFIG_OF_MTD.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

8 bits opcodes should be followed by a single address cycle. Make the
2nd address cycle dependent of !nand_opcode_8bits(command).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Setup the maximum ECC config when NAND_ECC_MAXIMIZE is set.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Add support for ECC maximization when software BCH with
nand_ooblayout_lp_ops layout is used.
Other cases should be handled by the NAND controller driver.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The generic NAND DT bindings allows one to tweak the ECC strength and
step size to their need. It can be used to lower the ECC strength to
match a bootloader/firmware config, but might also be used to get a better
reliability.

In the latter case, the user might want to use the maximum ECC strength
without having to explicitly calculate the exact value (this value not
only depends on the OOB size, but also on the NAND controller, and can
be tricky to extract).

Add a generic 'nand-ecc-maximize' DT property and the associated
NAND_ECC_MAXIMIZE flag, to let ECC controller drivers select the best
ECC strength and step-size on their own.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>

So far we relied on reset default or the bootloader to configure a
suitable clk rate for the Nand controller. This works but we can
optimize the timing for better performance. This sets the clk rate for
v2 controllers (i.MX25/35) based on the timing mode read from the ONFI
parameter page. This may also enable the symmetric mode (aks EDO mode)
if necessary which reads one word per clock cycle.
Tested on an i.MX25 with a Micron MT29F4G08ABBDAHC attached.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

To be able to support different ONFI timing modes we have to implement
the onfi_set_features and onfi_get_features. Tested on an i.MX25 SoC.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The NAND framework is now able to select the best NAND timings for us.
All we have to do is implement a ->setup_data_interface() function to
apply those timings and remove the timing selection code from the sunxi
driver.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The NAND framework provides several helpers to query timing modes supported
by a NAND chip, but this implies that all NAND controller drivers have
to implement the same timings selection dance. Also currently NAND
devices can be resetted at arbitrary places which also resets the timing
for ONFI chips to timing mode 0.

Provide a common logic to select the best timings based on ONFI or
->onfi_timing_mode_default information. Hook this into nand_reset()
to make sure the new timing is applied each time during a reset.

NAND controller willing to support timings adjustment should just
implement the ->setup_data_interface() method.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

The nand layer will need ONFI mode 0 to use it as timing mode
before and right after reset.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

onfi_init_data_interface() initializes a data interface with
values from a given ONFI mode.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

struct nand_data_interface is the designated type to pass to
the NAND drivers to configure the timing. To simplify further
patches convert the onfi_sdr_timings array from type struct
nand_sdr_timings nand_data_interface.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Currently we have no data structure to fully describe a NAND timing.
We only have struct nand_sdr_timings for NAND timings in SDR mode,
but nothing for DDR mode and also no container to store both types
of timing.
This patch adds struct nand_data_interface which stores the timing
type and a union of different timings. This can be used to pass to
drivers in order to configure the timing.
Add kerneldoc for struct nand_sdr_timings while touching it anyway.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

When NAND devices are resetted some initialization may have to be done,
like for example they have to be configured for the timing mode that
shall be used. To get a common place where this initialization can be
implemented create a nand_reset() function. This currently only issues
a NAND_CMD_RESET to the NAND device. The places issuing this command
manually are replaced with a call to nand_reset().
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

'extern' is not necessary for function declarations. To prevent
people from adding the keyword to new declarations remove the
existing ones.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Signed-off-by: Harvey Hunt <harveyhuntnexus@gmail.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Some Keystone devices (e.g. K2G) include a OMAP NAND IP.
Allow the NAND driver to be usable for both
Keystone and OMAP devices.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

This patch adds big endian and ONFI support for various iProc based
SoCs that use the core brcmstb NAND controller

This patch was originally implemented by Prafulla Kota
<prafulla.kota@broadcom.com> and fully tested on iProc based NS2 SVK
Signed-off-by: Prafulla Kota <prafulla.kota@broadcom.com>
Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Kamal Dasu <kdasu.kdev@gmail.com>
Acked-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

If erasing or writing the BBT fails, we should mark the current BBT
block as bad and use the BBT descriptor to scan for the next available
unused block in the BBT. We should only return a failure if there isn't
any space left.
Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com>
Suggested-by: Jeff Westfahl <jeff.westfahl@ni.com>
Tested-by: Kyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

This clarifies the write_bbt() function by removing the write label
and simplifying the error/exit path.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Kyle Roeschley <kyle.roeschley@ni.com>

In the ONFI spec, the tRR_min entry is defined before the tRST_max one.
Reoder the definition to make it easier to review.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

ONFI 4.0 spec defines different values for the tADL_min timing.
Since we don't want to have different timings depending on the ONFI
version, we just set tADL_min to the maximum value (the one specified
in the ONFI 4.0 spec).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

change the way to calculate pagesize to get correct free oob space for
legacy_set_geometry function.
Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Some build tools noticed that 'cookie' is being set but not used. Might
as well catch the errors here and handle them the same way we handle
other DMA prep steps.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The driver registered for CPU frequency transitions to recalculate its
clock when ARM clock frequency changes (ratio between frequencies of
ARM's parent clock (fclk) and clock for peripherals remains fixed).

This is needed only on S3C24xx platform when cpufreq driver is enabled
so limit the ifdef to respective cpufreq Kconfig.
Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Using "goto" and "switch" statement only makes it harder to follow
control flow and doesn't bring any advantages. Rewrite the code to avoid
using "goto".
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

If no user specified chip->select_chip() function is provided, code in
nand_base.c will automatically set this hook to nand_select_chip(),
which in turn depends on chip->cmd_ctrl() hook being valid. Not
providing both of those functions in NAND controller driver (for example
by mistake) will result in a bit cryptic segfault. Same is true for
chip->cmdfunc().

To avoid the above scenario add a check in nand_scan_dent and error out
if cmd_ctrl() is not provided.
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Suggested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Config MTD_NAND_FSL_IFC is already located inside 'if MTD_NAND'
statment, so there's no need to explicitly specify it as a dependency.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

MTD_NAND_FSL_ELBC selects FSL_LBC that in turn depends on FSL_SOC, so
depending on PPC instead of FSL_SOC leads to this message:

	  warning: (MPC836x_RDK && MTD_NAND_FSL_ELBC &&
	  MTD_NAND_FSL_UPM) selects FSL_LBC which has unmet direct
	  dependencies (FSL_SOC)

when doing

	  make ARCH=powerpc \
	       CROSS_COMPILE=powerpc-e500v2-linux-gnuspe- \
	       allmodconfig"

Changing dependency to FSL_SOC fixes that.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The code to initialize a struct nand_hw_control is duplicated across
several drivers. Factorize it using an inline function.
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

MLC and TLC NAND devices are using NAND cells exposing more than one bit,
but instead of attaching all the bits in a given cell to a single NAND
page, each bit is usually attached to a different page. This concept is
called 'page pairing', and has significant impacts on the flash storage
usage.
The main problem showed by these devices is that interrupting a page
program operation may not only corrupt the page we are programming
but also the page it is paired with, hence the need to expose to MTD
users the pairing scheme information.

The pairing APIs allows one to query pairing information attached to a
given page (here called wunit), or the other way around (the wunit
pointed by pairing information).
It also provides several helpers to help the conversion between absolute
offsets and wunits, and query the number of pairing groups.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Brian Norris <computersforpeace@gmail.com>

This fixes subpage writes when using 4-bit HW ECC.

There has been numerous reports about ECC errors with devices using this
driver for a while.  Also the 4-bit ECC has been reported as broken with
subpages in [1] and with 16 bits NANDs in the driver and in mach* board
files both in mainline and in the vendor BSPs.

What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to
try reinitializing the ECC engine:
- R/W on whole pages properly generates/checks RS code
- try writing the 1st subpage only of a blank page, the subpage is well
  written and the RS code properly generated, re-reading the same page
  the HW detects some ECC error, reading the same page again no ECC
  error is detected

Note that the ECC engine is already reinitialized in the 1-bit case.

Tested on my LCDK with UBI+UBIFS using subpages.
This could potentially get rid of the issue workarounded in [1].

[1] 28c015a9 ("mtd: davinci-nand: disable subpage write for keystone-nand")

Fixes: 6a4123e5 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage")
Cc: <stable@vger.kernel.org>
Signed-off-by: Karl Beldan <kbeldan@baylibre.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

dma_request_chan() can fail returning an error pointer. In this case
prevent calling dma_release_channel() to prevent a ERR_PTR() dereference.

As error path can be called even with no DMA configuration, info->dma can
be NULL so don't call dma_release_channel() for that case either.

Fixes: de3bfc4a: ("mtd: nand: omap2: fix return value check in omap_nand_probe()")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>