Since commit 6d178ef2 ("mtd: nand: Move ELM driver and rename as
omap_elm"), I don't have any mtd devices present on my am335x. This
changes the link order of the omap_elm and omap2 objects, causing them
to probe in the wrong order.

To fix this, make elm_config defer probing until the omap_elm driver is
actually loaded.
Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

m25p80's device ID table is now spi_nor_ids, defined in spi-nor.  The
MODULE_DEVICE_TABLE() macro doesn't work with extern definitions, but
its use was also removed at the same time.  Now if m25p80 is built as
a module it doesn't get the necessary aliases to be loaded
automatically.

A clean solution to this will involve defining the list of device
IDs in spi-nor.h and removing struct spi_device_id from the spi-nor
API, but this is quite a large change.

As a quick fix suitable for stable, copy the device IDs back into
m25p80.

Fixes: 03e296f6 ("mtd: m25p80: use the SPI nor framework")
Cc: <stable@vger.kernel.org> # 3.16.x: 32f1b7c8: mtd: move support for struct flash_platform_data into m25p80
Cc: <stable@vger.kernel.org> # 3.16.x: 90e55b38: mtd: m25p80: get rid of spi_get_device_id
Cc: <stable@vger.kernel.org> # 3.16.x: 70f3ce05: mtd: spi-nor: make spi_nor_scan() take a chip type name, not spi_device_id
Cc: <stable@vger.kernel.org> # 3.16.x
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Drivers currently call spi_nor_match_id() and then spi_nor_scan().
This adds a dependency on struct spi_device_id which we want to
avoid.  Make spi_nor_scan() do it for them.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This simplifies the way we use spi_nor framework and will allow us to
drop spi_nor_match_id.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The MTD_NAND_OMAP_BCH doesn't harm on legacy OMAP platforms
so don't state that it should be disabled for them.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This commit adds a hidden option to build the omap_elm as a module, if
omap2_nand is a module (and similarly in the built-in case).

This fixes the following build error when omap2_nand is chosen built-in,
and omap_elm is chosen as a module:

drivers/built-in.o: In function `omap_nand_probe':
drivers/mtd/nand/omap2.c:2010: undefined reference to `elm_config'
drivers/mtd/nand/omap2.c:1980: undefined reference to `elm_config'
drivers/mtd/nand/omap2.c:1927: undefined reference to `elm_config'
drivers/built-in.o: In function `omap_elm_correct_data':
drivers/mtd/nand/omap2.c:1444: undefined reference to `elm_decode_bch_error_page'
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This "type" seems to be an extra hint for m25p80 about the flash. Some
archs register flash_platform_data with "name" set to "m25p80" and then
with a real flash name set in "type". It seems to be a trick specific
to the m25p80 so let's move it out of spi-nor.
Btw switch to the spi_nor_match_id instead of iterating spi_nor_ids.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Current situation with 4K sectors is quite messy. First of all, some
MTD "users" don't work with such small size. An example may be UBIFS
which requires 15 KiB erase blocks as a minimum. In theory spi-nor
should provide multiple erase regions and MTD "users" should use the
one they need. Unforunately that is not implemented.

In the result our flashes database in spi-nor is hackish. For some
flashes we pretend they don't support 4K sectors just because some
distribution uses UBIFS on it. This ofc leads to conflicts, like
Samsung using w25q128 with 4K sectors vs. OpenWrt requiring it to
pretend it's 64 KiB blocks only.

My idea (plan?) for fixing this situation:
1) Use real hw info (this requires a way for disabling 4K for now)
2) Provide detailed info about erase regions
3) Make UBIFS work with devices that support 4K sectors
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The ELM driver is only used by the OMAP NAND driver, so let's move it
to the nand/ directory. Additionally, let's rename it to a less confusing
name, so the module is built with a meaningful name, instead of the previous
'elm.ko'.
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Usage of pr_err is frowned upon, so replace it with dev_err.
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The current code abuses ifdefs to determine if the selected ECC scheme
is supported by the running kernel. As a result the code is hard to read,
and it also fails to load as a module.

This commit removes all the ifdefs and instead introduces a function
omap2_nand_ecc_check() to check if the ECC is supported by using
IS_ENABLED(CONFIG_xxx).

Since IS_ENABLED() is true when a config is =y or =m, this change fixes the
module so it can be loaded with no issues.
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add the full description of the Hynix H27UCG8T2ATR-BC NAND chip in the
nand_ids table so that we can later use the NAND ECC infos and ONFI timings
mode in controller drivers.
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add an onfi_timing_mode_default field to nand_chip and nand_flash_dev in
order to support NAND timings definition for non-ONFI NAND.

NAND that support better timings mode than the default one have to define
a new entry in the nand_ids table.

The default timing mode should be deduced from timings description from
the datasheet and the ONFI specification
(www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf, chapter 4.15
"Timing Parameters").
You should choose the closest mode that fit the timings requirements of
your NAND chip.
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Previously, the only way to map a NOR device as a simple ROM was to
use the obsolete "direct-mapped" compatible binding (which further
requires device_type = "nor" and probe-type = "NOR" properties).

This patch adds an "mtd-rom" compatible binding to the "map_rom"
probe type.
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The "ROM" and unknown probe types within the obsolete "direct-mapped"
probe function used the nonexistent "mtd_rom" probe instead of the
intended "map_rom".
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

We've been semi-officially queueing patches here for a while, and it's
in linux-next, so let's advertise it in MAINTAINERS.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

- Fix indents
- Do not break a line unless it is longer than 80 columns
- Do not insert a whitespace before ';'
- Use whitespaces around operators
- Use braces for a "else" block where the "if" block uses ones.

Besides, eliminate all the warnings reported by checkpatch.pl:
- WARNING: quoted string split across lines
- WARNING: else is not generally useful after a break or return
- WARNING: Missing a blank line after declarations
- WARNING: Avoid line continuations in quoted strings
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

We should use parentheses only when they are necessary
or they really improve the readability.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The variable "irq_status" in denali_read_page_raw() is set, but not used.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

It looks like this header file is a concatenation of two headers.
Anyway, the include guard should be renamed and placed at the correct
postion and the license block in the middle should be deleted.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This follows Chapter 2 of Linux's CodingStyle:
> However, never break user-visible strings such as printk messages,
> because that breaks the ability to grep for them.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This won't be used by NAND subsystem as we implement cmdfunc on our
own, but will allow us to write a bit cleaner code.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

We are supposed to mask value, not multiply it. Add some comments btw.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Old devices used to have NVRAM at the very end of flash and they could
be unaligned (starting at some offset in a block).
In new devices NVRAM can be located quite randomly, however it seems to
always start at the beginning of a block. For example Netgear R6250 has
NVRAM located right after the bootloader, before the kernel partition.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

For PMECC, the pmecc_bytes_per_sector has same meaning as ecc.bytes.
So remove pmecc_bytes_per_sector and use ecc.bytes instead.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

For PMECC, the pmecc_sector_number has same meaning as ecc.steps.
So use ecc.steps to replace the pmecc_sector_number.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This commit adds a new platform-data boolean property that enables use
of a flash-based bad block table. This can also be enabled by setting
the 'nand-on-flash-bbt' devicetree property.

If the flash BBT is not enabled, the driver falls back to use OOB
bad block markers only, as before. If the flash BBT is enabled the
kernel will keep track of bad blocks using a BBT, in addition to
the OOB markers.

As explained by Brian Norris the reasons for using a BBT are:

""
The primary reason would be that NAND datasheets specify it these days.
A better argument is that nobody guarantees that you can write a
bad block marker to a worn out block; you may just get program failures.

This has been acknowledged by several developers over the last several
years.

Additionally, you get a boot-time performance improvement if you only
have to read a few pages, instead of a page or two from every block on
the flash.
""
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Brian 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: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The variable "retry" in wait_for_irq() is set, but not used.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

We should rathar use "int" type for loop iterators.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Useless casts result in unreadable source code.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

All of these variables are initialized to zero and then
set to a different value below.
Zero-initializing is redundant.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

We should use
/*
 * Blah Blah ...
 * ...
 */

for multi-line comment blocks.

In addition, refactor some comments where it seems reasonable and
remove some comments where the code is clear enough such as:

    /* clear interrupts */
    clear_interrupts(denali);
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Pull vfs fixes from Al Viro:
 "double iput() on failure exit in lustre, racy removal of spliced
  dentries from ->s_anon in __d_materialise_dentry() plus a bunch of
  assorted RCU pathwalk fixes"

The RCU pathwalk fixes end up fixing a couple of cases where we
incorrectly dropped out of RCU walking, due to incorrect initialization
and testing of the sequence locks in some corner cases.  Since dropping
out of RCU walk mode forces the slow locked accesses, those corner cases
slowed down quite dramatically.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  be careful with nd->inode in path_init() and follow_dotdot_rcu()
  don't bugger nd->seq on set_root_rcu() from follow_dotdot_rcu()
  fix bogus read_seqretry() checks introduced in b37199e6
  move the call of __d_drop(anon) into __d_materialise_unique(dentry, anon)
  [fix] lustre: d_make_root() does iput() on dentry allocation failure

The performance regression that Josef Bacik reported in the pathname
lookup (see commit 99d263d4 "vfs: fix bad hashing of dentries") made
me look at performance stability of the dcache code, just to verify that
the problem was actually fixed.  That turned up a few other problems in
this area.

There are a few cases where we exit RCU lookup mode and go to the slow
serializing case when we shouldn't, Al has fixed those and they'll come
in with the next VFS pull.

But my performance verification also shows that link_path_walk() turns
out to have a very unfortunate 32-bit store of the length and hash of
the name we look up, followed by a 64-bit read of the combined hash_len
field.  That screws up the processor store to load forwarding, causing
an unnecessary hickup in this critical routine.

It's caused by the ugly calling convention for the "hash_name()"
function, and easily fixed by just making hash_name() fill in the whole
'struct qstr' rather than passing it a pointer to just the hash value.

With that, the profile for this function looks much smoother.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>