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: Brian Norris <computersforpeace@gmail.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Harvey Hunt <harvey.hunt@imgtec.com>
Acked-by: Harvey 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: Harvey 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris 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: Brian Norris <computersforpeace@gmail.com>
Cc: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

New helpers have been added to avoid directly accessing chip->field. Use
them where appropriate.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

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

New helpers have been added to avoid directly accessing chip->field. Use
them where appropriate.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add two helpers to access the field reserved for private controller data.
This makes it clearer what this field is reserved for and ease future
refactoring.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Alex 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: Harvey Hunt <harvey.hunt@imgtec.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Brian: fixed a few small mistakes]
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Franklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Franklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Franklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add DT bindings for NAND devices connected to the NEMC on JZ4780 SoCs,
as well as the hardware BCH controller, used by the jz4780_{nand,bch}
drivers.
Signed-off-by: Alex 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: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

kmalloc needs to be handled when failing in memory pressure.
Also, it has memory leak in error routine.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

On Micron and Numonyx devices, the status register write command
(WRSR), raises a work-in-progress bit (WIP) on the status register.
The datasheets for these devices specify that while the status
register write is in progress, the status register WIP bit can still
be read to check the end of the operation.

This commit adds a wait_till_ready call on lock/unlock operations,
which is required for Micron and Numonyx but should be harmless for
others. This is needed to prevent applications from issuing erase or
program operations before the unlock operation is completed.
Reported-by: Stas Sergeev <stsp@list.ru>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This is an API consolidation only. The use of kmalloc + memset to 0
is equivalent to kzalloc.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Use to_delayed_work() instead of open-coding it.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Brian 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: Heiko Schocher <hs@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Heiko Schocher <hs@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Frans Klaver <fransklaver@gmail.com>
Cc: <stable@vger.kernel.org>

Small conflict between some bugfixes for 4.4 and some refactoring for
4.5.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

stm_is_locked_sr() takes the status register (SR) value as the last
parameter, not the second.
Reported-by: Bayi Cheng <bayi.cheng@mediatek.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Bayi Cheng <bayi.cheng@mediatek.com>

Spansion and Winbond have occasionally used the same manufacturer ID,
and they don't support the same features. Particularly, writing SR=0
seems to break read access for Spansion's s25fl064k. Unfortunately, we
don't currently have a way to differentiate these Spansion and Winbond
parts, so rather than regressing support for these Spansion flash, let's
drop the new Winbond lock/unlock support for now. We can try to address
Winbond support during the next release cycle.

Original discussion:

http://patchwork.ozlabs.org/patch/549173/
http://patchwork.ozlabs.org/patch/553683/

Fixes: 357ca38d ("mtd: spi-nor: support lock/unlock/is_locked for Winbond")
Fixes: c6fc2171 ("mtd: spi-nor: disable protection for Winbond flash at startup")
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reported-by: Felix Fietkau <nbd@openwrt.org>
Cc: Felix Fietkau <nbd@openwrt.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: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Commit 807f16d4 ("mtd: core: set some defaults when dev.parent is
set") attempted to provide some default settings for MTDs that
 (a) assign the parent device and
 (b) don't provide their own name or owner

However, this isn't a perfect drop-in replacement for the boilerplate
found in some drivers, because the MTD name is used by partition
parsers like cmdlinepart, but the name isn't set until add_mtd_device(),
after the parsing is completed. This means cmdlinepart sees a NULL name
and therefore will not work properly.

Fix this by moving the default name and owner assignment to be first in
the MTD registration process.

[Note: this does not fix all reported issues, particularly with NAND
drivers. Will require an additional fix for drivers/mtd/nand/]

Fixes: 807f16d4 ("mtd: core: set some defaults when dev.parent is set")
Reported-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Frans Klaver <fransklaver@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: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Brian 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: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Brian 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: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Move write data register before excute command to avoid
missing first byte write to nor flash
Signed-off-by: Bayi Cheng <bayi.cheng@mediatek.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: 711fdf62 ("[MTD] [NAND] platform NAND driver: add driver")
Cc: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Brian 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Now that all drivers are using the mtd instance embedded in the nand_chip
struct we can safely update the mtd_to_nand() implementation to use
the container_of macro instead of returning the content of mtd->priv.
This will allow us to remove mtd->priv = chip assignments done in all
NAND controller drivers.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

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

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