The Armada BCH configuration in this driver uses one of the two
following ECC schemes:

 16-bit correction per 2048 bytes
 16-bit correction per 1024 bytes

These are sufficient for mapping to the 4-bit per 512-bytes and 8-bit
per 512-bytes (respectively) minimum correctability requirements of many
common NAND.

The current code only checks for the required strength (4-bit or 8-bit)
without checking the ECC step size that is associated with that strength
(and simply assumes it is 512). While that is often a safe assumption to
make, let's make it explicit, since we have that information.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>

This commit extends the ECC correctable error detection to include
ECC BCH errors. The number of BCH correctable errors can be any up to 16,
and the actual value is exposed in the NDSR register.

Therefore, we change some symbol names to refer to correctable or
uncorrectable (instead of single-bit or double-bit as it was in the
Hamming case) and while at it, cleanup the detection code slightly.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This commit adds write support for large pages (4 KiB, 8 KiB).
Such support is implemented by issuing a multiple command sequence,
transfering a set of 2 KiB chunks per transaction.

The splitted command sequence requires to send the SEQIN command
independently of the PAGEPROG command and therefore it's set as
an execution command.

Since PAGEPROG enables ECC, each 2 KiB chunk of data is written
together with ECC code at a controller-fixed location within
the flash page.

Currently, only devices with a 4 KiB page size has been tested.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

As preparation work to fully support large pages, this commit adds
the initial infrastructure to support splitted (aka chunked) I/O
operation. This commit adds support for read, and follow-up patches
will add write support.

When a read (aka READ0) command is issued, the driver loops issuing
the same command until all the requested data is transfered, changing
the 'extended' command field as needed.

For instance, if the driver is required to read a 4 KiB page, using a
chunk size of 2 KiB, the transaction is splitted in:
1. Monolithic read, first 2 KiB page chunk is read
2. Last naked read, second and last 2KiB page chunk is read

If ECC is enabled it is calculated on each chunk transfered and added
at a controller-fixed location after the data chunk that must be
spare area.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In preparation to support multiple (aka chunked, aka splitted)
page I/O, this commit adds 'data_buff_pos' and 'oob_buff_pos' fields
to keep track of where the next read (or write) should be done.

This will allow multiple calls to handle_data_pio() to continue
the read (or write) operation.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This commit adds support page programming with a non-zero "column"
address setting. This is important to support OOB writing, through
command sequences such as:

  cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, ofs);
  write_buf(mtd, oob_buf, 6);
  cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

To allow future support of multiple page reading/writing, move the data
buffer clean out of prepare_set_command().

This is done to prevent the data buffer from being cleaned on every command
preparation, when a multiple command sequence is implemented to read/write
pages larger than the FIFO size (2 KiB).
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This commit splits the prepare_command_pool() function into two
stages: prepare_start_command() / prepare_set_command().

This is a preparation patch without any functionality changes,
and is meant to allow support for multiple page reading/writing
operations.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

READ0 and READOOB command preparation has a falltrough to SEQIN
case, where the command address is specified.
This is certainly confusing and makes the code less readable with
no added value. Let's remove it.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Let's simplify the code by first introducing a helper function
to set the page address, as done by the READ0, READOOB and SEQIN
commands.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Command buffer #3 is not properly cleared and it keeps the last
set value. Fix this by clearing when a command is setup.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This commit adds the BCH ECC support available in NFCv2 controller.
Depending on the detected required strength the respective ECC layout
is selected.

This commit adds an empty ECC layout, since support to access large
pages is first required. Once that support is added, a proper ECC
layout will be added as well.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add support for flash-based bad block table using Marvell's
custom in-flash bad block table layout. The support is enabled
a 'flash_bbt' platform data or device tree parameter.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In pxa3xx_nand_sensing() instead of simply using info->is_ready
after issuing a command, the correct way of checking is to wait
for the device to be ready through the chip's waitfunc().
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The expected behavior of the waitfunc() NAND chip call is to wait
for the device to be READY (this is a standard chip line).
However, the current implementation does almost nothing, which opens
the possibility of issuing a command to a non-ready device.

Fix this by adding a new completion to wait for the ready event to arrive.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add a comment clarifying the use of pxa3xx_set_datasize() which is only
applicable on data read/write commands (i.e. commands with a data cycle,
such as READID, READ0, STATUS, etc.)
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

There's no need to privately store the device page size as it's
available in mtd structure field mtd->writesize.
Also, this removes the hardcoded page size value, leaving the
auto-detected value only.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Introduce a fifo_size field to represent the size of the controller's
FIFO buffer, and use it to distinguish that size from the amount
of data bytes to be read from the FIFO.

This is important to support devices with pages larger than the
controller's internal FIFO, that need to read the pages in FIFO-sized
chunks.

In particular, the current code is at least confusing, for it mixes
all the different sizes involved: FIFO size, page size and data size.

This commit starts the cleaning by removing the info->page_size field
that is not currently used. The host->page_size field should also
be removed and use always mtd->writesize instead. Follow up commits
will clean this up.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Whenever possible, it's always better to use the generic chip->cmdfunc
instead of the internal pxa3xx_nand_cmdfunc().
In this particular case, this will allow to have multiple cmdfunc()
implementations for different SoC variants.
Reviewed-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In order to customize early settings depending on the detected SoC variant,
move the detection to be before the nand_chip struct filling.

In a follow-up patch, this change is needed to detect the variant *before*
the call to alloc_nand_resource(), which allows to set a different cmdfunc()
for each variant.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

As per the ecc.read_page() prototype, we must return the maximum number
of bitflips that were corrected on any one region covering an ecc step.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The current driver doesn't support sub-page writing, so report
that to the NAND core.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Given there's no public specification to this date, and in order
to capture some important details and singularities about the
controller let's document them once and for good.

Cc: linux-doc@vger.kernel.org
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In commit:

  commit 62e8b851
  Author: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
  Date:   Fri Oct 4 15:30:38 2013 -0300

  mtd: nand: pxa3xx: Allocate data buffer on detected flash size

the way the buffer is allocated was changed: the first READ_ID is issued
with a small kmalloc'ed buffer. Only once the flash page size is detected
the DMA buffers are allocated, and info->use_dma is set.

Currently, if the device detection fails, the driver checks the 'use_dma'
module parameter and tries to release unallocated DMA resources.

Fix this by checking the proper indicator of the DMA allocation, which
is 'info->use_dma'.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This partially reverts c0f3b864.

The "armada370-nand" compatible support is not complete, and it was mistake
to add it. Revert it and postpone the support until the infrastructure is
in place.

Cc: <stable@vger.kernel.org> # 3.12
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This commit replaces the currently hardcoded buffer size, by a
dynamic detection scheme. First a small 256 bytes buffer is allocated
so the device can be detected (using READID and friends commands).

After detection, this buffer is released and a new buffer is allocated
to acommodate the page size plus out-of-band size.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Instead of setting info->dma each time a command is prepared,
we can move it after the DMA buffers are allocated.

This is more clear and it's the proper place to enable this, given
DMA cannot be turned on and off during runtime.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In a recent commit:

  commit f455578d
  Author: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
  Date:   Mon Aug 12 14:14:53 2013 -0300

  mtd: nand: pxa3xx: Remove hardcoded mtd name

  There's no advantage in using a hardcoded name for the mtd device.
  Instead use the provided by the platform_device.

The MTD name was changed to use the one provided by the platform_device.
However, this can be problematic as some users want to set partitions
using the kernel parameter 'mtdparts', where the name is needed.

Therefore, to avoid regressions in users relying in 'mtdparts' we revert
the change and use the previous one 'pxa3xx_nand-0'.

While at it, let's put a big comment and prevent this change from happening
ever again.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

There's no need to enclose this code within idef CONFIG_OF,
because the OF framework provides no-op stubs if CONFIG_OF=n.

Cc: devicetree@vger.kernel.org
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

When use_dma=0 there's no point in requesting resources for dma,
since they won't be used anyway. Therefore we remove that requirement,
therefore allowing devices without dma to pass the driver probe.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Now that we have added ARCH_HAS_DMA conditional the function
enable_int() may be unused. Declare it as __maybe_unused,
in order to remove the following warning, when the function is not used:

drivers/mtd/nand//pxa3xx_nand.c:343:24: warning: 'enable_int' defined
but not used [-Wunused-function]
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds a macro ARCH_HAS_DMA to compile-out arch specific
dma code, namely pxa_request_dma() and pxa_free_dma(). These symbols
are available only in pxa, which makes impossible to build the driver in
other platforms than ARCH_PXA.

In order to handle non-dma capable platforms, we implement a fallbacks that
allocate buffers as if 'use_dma=false', putting the dma related code
under the ARCH_HAS_DMA conditional.

Please note that the correct way to handle this is to migrate the
dma code to use of the mmp_pdma dmaengine driver. However, currently
this is not possible because the two dmaengine drivers can't work together.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This registers are not per-chip (aka host) but controller-wide,
so it's better to store them in the global 'info' structure.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Use the defined macros for NAND command instead of using a constant
internal structure. This commit is only a cleanup, there's no
functionality modification.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

There's no advantage in using a hardcoded name for the mtd device.
Instead use the provided by the platform_device.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This is just a cosmetic change, to make the code more readable.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The ONFI command 'parameter page read' needs a non-standard length.
Therefore, we enable the 'length override' field in NDCB0 and set
a non-zero 'length count' in NDCB3.

Additionally, the 'spare enable' bit must be disabled for any command
that sets a non-zero 'length count' in NDCB3.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Some newer controllers support a fourth command buffer. This additional
command buffer allows to set an arbitrary length count, using the
NDCB3.NDLENCNT field, to perform non-standard length operations
such as the ONFI parameter page read.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>