Since commit 17799359 ("mtd: nand_bbt:
make nand_scan_bbt() static"), the nand_scan_bbt() function is marked
as static but is still exported using EXPORT_SYMBOL(), which doesn't
make much sense.

This commit gets rid of the useless EXPORT_SYMBOL.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Suggested-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

When using multi-bit ECC, it is normal for the NAND Flash driver to
correct bit errors during the life of the product. Those errors will
only be cleared once a threshold has been reached, and corrections can
occur regularly before this.

Use only dev_dbg and not dev_info to report the bitflips, to keep the
system log clean when everything works correctly.
Signed-off-by: NRomain Izard <romain.izard.pro@gmail.com>
Acked-by: NWenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add support for the randomizer engine available in Allwinner's NFC IP.

Randomization is useful to support modern NAND chips which are sensitive to
repeated patterns. On such NANDs you might experience an unexpectedly high
number of bitflips when you repeat the same pattern all over a given NAND
block.
Randomizing input data mitigate this problem by avoiding such repeated
patterns.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The H27UCG8T2ATR-BC requires an external data scrambler. Reflect this
constraint in the nand_flash_ids definition.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The current code is the same as 'of_machine_is_compatible'.
So use it in order to remove a few lines of code and to be more
consistent with other parts of the kernel.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The nuc900_nand driver has always passed an incorrect register
address in its nuc900_check_rb() function, which cannot possibly
work, and in some configurations gives us a build warning:

drivers/mtd/nand/nuc900_nand.c: In function 'nuc900_check_rb':
drivers/mtd/nand/nuc900_nand.c:27:23: warning: passing argument 1 of '__raw_readl' makes pointer from integer without a cast [-Wint-conversion]
 #define REG_SMISR     0xac
drivers/mtd/nand/nuc900_nand.c:118:20: note: in expansion of macro 'REG_SMISR'
  val = __raw_readl(REG_SMISR);

This makes sure we actually read from the register rather than
from (void *)0x000000ac in user space.

I suspect nobody noticed this before because the nuc900_nand_devready()
function never gets called, or nobody uses this driver on an upstream
kernel. Possibly even both.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Using switch/case helps make this logic more clear and more robust. With
this structure:

 * it's clear that this driver only support ECC_{HW,SOFT,SOFT_BCH}; and

 * we can sanely handle new ECC unsupported modes (right now, this code
   makes incorrect assumptions about the possible values in the
   nand_ecc_modes_t enum; e.g., what happens with NAND_ECC_HW_OOB_FIRST?)
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NHarvey Hunt <harvey.hunt@imgtec.com>
Acked-by: NHarvey Hunt <harvey.hunt@imgtec.com>

Update jz4780_bch_ecc_correct's return codes with appropriate values,
as specified in /include/linux/mtd/nand.h.
Signed-off-by: NHarvey Hunt <harvey.hunt@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Commit d699ed25 ("mtd: nand: make use of
nand_set/get_controller_data() helpers") overlooked some uses of
nand_chip::priv.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

As of commit 2d3b77ba ("mtd: nand: update mtd_to_nand()"), this
assignment isn't necessary, since struct mtd_info is embedded in struct
nand_chip.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

New helpers have been added to avoid directly accessing chip->field. Use
them where appropriate.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
[Brian: fixed a few rebase conflicts]
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
well as the hardware BCH controller. DMA is not currently implemented.

While older 47xx SoCs also have a BCH controller, they are incompatible
with the one in the 4780 due to differing register/bit positions, which
would make implementing a common driver for them quite messy.
Signed-off-by: NAlex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NHarvey Hunt <harvey.hunt@imgtec.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
[Brian: fixed a few small mistakes]
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The jz4740 driver is manually checking for 'erased pages' while
correcting ECC bytes.
This logic can now done by the core infrastructure, and can thus be removed
from this driver.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The diskonchip driver is manually checking for 'erased pages' while
correcting ECC bytes.
This logic can now done by the core infrastructure, and can thus be removed
from this driver.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The davinci driver is manually checking for 'erased pages' while
correcting ECC bytes.
This logic can now done by the core infrastructure, and can thus be removed
from this driver.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NFranklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The default NAND read functions are relying on the underlying controller
driver to correct bitflips, but some of those controllers cannot properly
fix bitflips in erased pages.
Check for bitflips in erased pages in default core functions if the driver
delegated the this check by setting the NAND_ECC_GENERIC_ERASED_CHECK flag.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NFranklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The error code returned by the ecc.correct() are not consistent over the
all implementations.

Document the expected behavior in include/linux/mtd/nand.h and fix
offending implementations.

[Brian: this looks like a bugfix for the ECC reporting in the bf5xx_nand
driver, but we haven't seen any testing results for it]
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NFranklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Commits such as commit 853f1c58 ("mtd: nand: omap2: show parent
device structure in sysfs") attempt to rely on the core MTD code to set
the MTD name based on the parent device. However, nand_base tries to set
a different default name according to the flash name (e.g., extracted
from the ONFI parameter page), which means NAND drivers will never make
use of the MTD defaults. This is not the intention of commit
853f1c58.

This results in problems when trying to use the cmdline partition
parser, since the MTD name is different than expected. Let's fix this by
providing a default NAND name, where possible.

Note that this is not really a great default name in the long run, since
this means that if there are multiple MTDs attached to the same
controller device, they will have the same name. But that is an existing
issue and requires future work on a better controller vs. flash chip
abstraction to fix properly.

Fixes: 853f1c58 ("mtd: nand: omap2: show parent device structure in sysfs")
Reported-by: NHeiko Schocher <hs@denx.de>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NHeiko Schocher <hs@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Frans Klaver <fransklaver@gmail.com>
Cc: <stable@vger.kernel.org>

From Stephen:

    Hi Brian,

    After merging the l2-mtd tree, today's linux-next build (powerpc
    ppc44x_defconfig) failed like this:

    drivers/mtd/nand/ndfc.c: In function 'ndfc_chip_init':
    drivers/mtd/nand/ndfc.c:177:2: error: 'ppdata' undeclared (first use in this function)
      ppdata.of_node = flash_np;
      ^

    Caused by commit

      a61ae81a ("mtd: nand: drop unnecessary partition parser data")

The flash node is already correctly assigned using the new helper
(nand_set_flash_node()) so the correct fix is indeed to simply drop this
line.

Fixes: a61ae81a ("mtd: nand: drop unnecessary partition parser data")
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

By convention, the FIFO address we pass using dmaengine_slave_config
is a physical address in the form that is understood by the DMA
engine, as a dma_addr_t, phys_addr_t or resource_size_t.

The sh_flctl driver however passes a virtual __iomem address that
gets cast to dma_addr_t in the slave driver. This happens to work
on shmobile because that platform sets up an identity mapping for
its MMIO regions, but such code is not portable to other platforms,
and prevents us from ever changing the platform mapping or reusing
the driver on other architectures like ARM64 that might not have the
mapping.

We also get a warning about a type mismatch for the case that
dma_addr_t is wider than a pointer, i.e. when CONFIG_LPAE is set:

drivers/mtd/nand/sh_flctl.c: In function 'flctl_setup_dma':
drivers/mtd/nand/sh_flctl.c:163:17: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  cfg.dst_addr = (dma_addr_t)FLDTFIFO(flctl);

This changes the driver to instead pass the physical address of
the FIFO that is extracted from the MMIO resource, making the
code more portable and avoiding the warning.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The build passes even if CONFIG_OF is undefined, but it makes sense
to let it depend on OF.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

nand_write_subpage_hwecc causes a crash if the driver did not register
ecc->hwctl or ecc->calculate. Fix this by disabling subpage writes if
ecc->hwctl or ecc->calculate is not provided by the driver.

This behavior was introduced in commit 837a6ba4
"mtd: nand: subpage write support for hardware based ECC schemes".

This fixes a crash with fsl_elbc_nand and maybe others:

Unable to handle kernel paging request for instruction fetch
Faulting instruction address: 0x00000000
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2 P1020 RDB
Modules linked in: ath9k ath9k_common pppoe ppp_async option iptable_nat ath9k_hw ath usb_wwan pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv4 mac80211 ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_quota xt_policy xt_pkttype xt_owner xt_nat xt_multiport xt_mh
CPU: 1 PID: 2161 Comm: ubiformat Not tainted 3.10.26 #6
task: efbc2700 ti: c7950000 task.ti: c7950000
NIP: 00000000 LR: c01a495c CTR: 00000000
REGS: c7951cb0 TRAP: 0400   Not tainted  (3.10.26)
MSR: 00029000 <CE,EE,ME>  CR: 24002028  XER: 00000000

GPR00: c01a4b6c c7951d60 efbc2700 ef84b000 00000001 00000000 000001ff c7800500
GPR08: 00000000 00000000 efae5e40 c01a4ae4 24002022 10023418 c7951e5c c7800500
GPR16: c017b6a8 00000000 0000003f c053404c 00000000 00000004 00000000 00000003
GPR24: 00000010 00000200 ef84b000 c7800d00 c7800000 c7800500 ef84b1c8 00000000
NIP [00000000]   (null)
LR [c01a495c] nand_write_subpage_hwecc+0x74/0x174
Call Trace:
[c7951d60] [c7951d64] 0xc7951d64 (unreliable)
[c7951da0] [c01a4b6c] nand_write_page+0x88/0x198
[c7951dd0] [c01a5f7c] nand_do_write_ops+0x2f4/0x39c
[c7951e40] [c01a61e0] nand_write+0x58/0x84
[c7951e80] [c019e29c] mtdchar_write+0x1dc/0x28c
[c7951ef0] [c00aba84] vfs_write+0xcc/0x1ac
[c7951f10] [c00ac04c] SyS_write+0x4c/0x90
[c7951f40] [c000cd84] ret_from_syscall+0x0/0x3c
 --- Exception: c01 at 0x48050ed8
     LR = 0x100071b8
 Instruction dump:
 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
 ---[ end trace 161d3c65a2a15cb8 ]---

Kernel panic - not syncing: Fatal exception

[Brian: editorial note - we've applied a previous fix for the driver in
question (fsl_elbc_nand) long ago:
commit f034d87d ("mtd: eLBC NAND: fix subpage write support")
but this still makes sense, and it could solve issues on some other
unforseen driver.]

Cc: Pekon Gupta <pekon.gupta@gmail.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Nobody uses the get_platform_nandchip() helper function which is supposed
to return a pointer to a platform_nand_chip struct from an mtd_info
pointer.
Moreover, this function is buggy since the introduction of the plat_nand
layer (chip->priv is now storing a pointer to an intermediate
plat_nand_data structure allocated in plat_nand_probe(), and we have no
way to retrieve a pointer to the provided platform_nand_chip struct from
this plat_nand_data pointer).

While we are at it, remove the useless (and buggy, since it's pointing to
something stored on the stack) data->chip.priv assignment.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Fixes: 711fdf62 ("[MTD] [NAND] platform NAND driver: add driver")
Cc: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Now that the nand_chip struct directly embeds an mtd_info struct we can
get rid of the ->flash_node field and forward set/get_flash_node requests
to the MTD layer.

As a side effect, we no longer need the mtd_set_of_node() call done in
nand_dt_init().
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

nand_dt_init() function requires 3 arguments where it actually needs one
(dn and mtd can both be retrieved from chip). Drop these parameters.

Testing for dn != NULL inside nand_dt_init() also helps simplifying the
caller code.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

mtd_to_nand() now uses the container_of() approach to transform an
mtd_info pointer into a nand_chip one. Drop useless mtd->priv
assignments from NAND controller drivers.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Other refactorings have left the 'fail' label much simpler, so it
shouldn't have to handle the failed allocation case.

This also fixes a -Wshadow warning.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

struct nand_chip now embeds an mtd device. Make use of this mtd instance.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>