In case of error, the function dma_request_chan() returns ERR_PTR() and
never returns NULL. The NULL test in the return value check should be
replaced with IS_ERR().

Fixes: aa7abd31 ('mtd: nand: omap2: Support parsing dma channel
information from DT')
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Pull NAND changes from Boris Brezillon:
"""
This pull request contains only one notable change:
* Addition of the MTK NAND controller driver

And a bunch of specific NAND driver improvements/fixes. Here are the
changes that are worth mentioning:
* A few fixes/improvements for the xway NAND controller driver
* A few fixes for the sunxi NAND controller driver
* Support for DMA in the sunxi NAND driver
* Support for the sunxi NAND controller IP embedded in A23/A33 SoCs
* Addition for bitflips detection in erased pages to the brcmnand driver
* Support for new brcmnand IPs
* Update of the OMAP-GPMC binding to support DMA channel description
"""

This patch documents the DT bindings for the driver of the Atmel QSPI
controller embedded inside sama5d2x SoCs.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add hisilicon spi-nor flash controller driver
Signed-off-by: Binquan Peng <pengbinquan@hisilicon.com>
Signed-off-by: Jiancheng Xue <xuejiancheng@hisilicon.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Jagan Teki <jteki@openedev.com>
Reviewed-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Gigadevice flash support BP{0,1,2,3,4} bits, where BP3 means the same as
the existing supported TB (Top/Bottom), and BP4 means the same as the
not-yet-supported 4K bit used on other flash (e.g., Winbond). Let's
support lock/unlock with the same feature flags as w25q32dw/w25q64dw.

Tested on gd25lq64c, but I checked datasheets for the other 3, to make
sure.

While I was at it, I noticed that these all support dual and quad as
well. I noted them, but can't test them at the moment, since my test
system only supports standard 1x SPI.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add Micron (n25q00a) 1Gbit NOR Flash in the list of supported
devices.
This part is different from n25q00 in Memory Type.
Memory Type for n25q00 - BAh
Memory Type for n25q00a - BBh
Signed-off-by: P L Sai Krishna <lakshmis@xilinx.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch enables IFC NAND support on ARM layerscape platform.
It fixes the dependency to enable NAND. The include files are being modified
to ensure complilation for both PowerPC and ARM architectures.
Signed-off-by: Raghav Dogra <raghav.dogra@nxp.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Emails will bounce from my imgtec address, so update it to a new one.
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: Harvey Hunt <harveyhuntnexus@gmail.com>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

I moved the sanity check on ecc->size before the allocation so that we
don't leak memory on error.

Fixes: 05af074a4b73 ('mtd: nand: sunxi: check ecc->size values')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The NAND controller on some sun8i chips needs its reset line to be
deasserted before they can enter working state.
Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Document the reset lines
Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Instead of using IO_ADDR_W and IO_ADDR_R use an own pointer to the NAND
controller memory area.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

This driver needs a special write_buf and read_buf function, because we
have to read from a specific address to tell the controller this is a
read from the nand controller.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Extract the functions to read and write to the register of the NAND
flash controller.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The external Bus Unit (EBU) can control different flash devices, but
these NAND flash commands have to be atomic and should not be
interrupted in between. Lock the EBU from the beginning of the command
till the end by moving the lock to the chip select.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

nand_scan() already resets the NAND flash chip, this driver does not
have to call it manually. The xway_reset_chip() functions does the same
as the normal NAND reset function. The waiting for the NAND_WAIT_WR_C
is done in xway_cmd_ctrl().
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The ->cmd_ctrl() function is adjusting the ->IO_ADDR_W value depending
on the command type each time NAND_CTRL_CHANGE is passed. This is not
only useless but can lead to an ->IO_ADDR_W corruption.

Get rid of this logic and rely on the NAND_CLE and NAND_ALE flags to
deduce the iomem address to write the cmd argument to.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Instead of hacking this into the plat_nand driver just make this a
normal nand driver.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

This adds some register documentation which should make it easier to
understand how this controller works. In addition it makes now use of
BIT() macro and adds some more defines.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Support for NAND biterrors test on platforms without raw write

While the default test mode relies on raw write (mtd_write_oob) to introduce
bit errors into a page, the rewrite test mode doesn't need it.

Changed the overwrite test to use normal writes. The default test mode
is unaffected and still requires raw write as before.
Signed-off-by: Iwo Mergler <Iwo.Mergler@netcommwireless.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Implement ecc->write_subpage() to prevent core code from assigning this
hook to nand_write_subpage_hwecc(). This default implementation tries
to call ecc->hwctl() which in our case is NULL, thus leading to a NULL
pointer dereference.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Verify that the ecc->size value is either 512 or 1024 bytes.
This should always be the case if this field was assigned to the
nand->ecc_step_size_ds value, but can be wrong when the user overloaded
this value with the nand-ecc-step-size DT property.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Switching to 1k ECC blocks when possible provides better resistance against
concentrated bitflips. Say you have those two configurations:

1/ 16bits/512bytes
2/ 32bits/1024bytes

Both of them require the same amount of ECC bytes (only true for this
specific engine), but the second config allows you to correct the case
where most of your bitflips are concentrated in a single 512bytes portion.

This fact makes the 1k ECC block size more advantageous than the 512bytes
one.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The column address passed to the RNDOUT operation was missing the page
size offset.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: 614049a8 ("mtd: nand: sunxi: add support for DMA assisted operations")

Add support for mediatek's SDG1 NFC nand controller embedded in SoC
2701
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Xiaolei Li <xiaolei.li@mediatek.com>

Documentation support for Smart Device Gen1 type of NAND controllers
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

In case of error, the function dmaengine_prep_slave_sg() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Fixes: 614049a8 ("mtd: nand: sunxi: add support for DMA assisted operations")
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

This change provides a fix for controller bug where nand
controller could have a possible sticky error after a PIO
followed by a DMA read. The fix retries a read if we see
a uncorr_ecc after read to detect such sticky errors.
The fix applies to only controller version 7.0 and 7.1.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

In stm_unlock(), the test to determine whether we've fully unlocked the
flash checks for the lock length to be equal to the flash size. That is
a typo/think-o -- the condition actually means the flash is completely
*locked.* We should be using the inverse condition -- that the lock
length is 0 (i.e., no protection).

The result of this bug is that we never actually turn off the Status
Register Write Disable bit, even if the flash is completely unlocked.
Now we can.

Fixes: 47b8edbf ("mtd: spi-nor: disallow further writes to SR if WP# is low")
Reported-by: Giorgio <giorgio.nicole@arcor.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

This function compiles to 2554 bytes of machine code.
In C, the function is almost 200 lines long.

It has only one callsite, but forced inlining that much code
makes gcc generate significantly worse code. Let gcc itself decide
what to do.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: David Woodhouse <David.Woodhouse@intel.com>
CC: Dan Carpenter <dan.carpenter@oracle.com>
CC: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
CC: linux-mtd@lists.infradead.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Replace if condition and BUG() with a BUG_ON having the conditional
expression of the if statement as argument.

The Coccinelle semantic patch used to make this change is as follows:
@@ expression E,f; @@

(
  if (<+... f(...) ...+>) { BUG(); }
|
- if (E) { BUG(); }
+ BUG_ON(E);
)
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/maps/physmap_of.c: In function ‘of_flash_probe’:
drivers/mtd/maps/physmap_of.c:165:16: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]

This could be a problem if the 'reg' property is not set, since that
means 'count' will be uninitialized.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The "tmp_retlen" variable can be uninitialized if action() fails.  It's
harmless except for the static checker warning.  I have moved the error
handling earlier to fix it.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This has been unused, except as the condition for a fatal error, since
commit c13cbf3b ("[MTD] mtdram: Quick cleanup of the driver:") in
2.6.13 (!).
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Check for erased page bitflips in a page. And if well within
threshold return data as all 0xff. Apply sw check for controller
version < 7.2. Controller vesion >= 7.2 has hw support.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

I got device with ESMT (Elite Semiconductor Memory Technology Inc)
F59L1G81MA flash that was detected as:
[    0.852034] nand: device found, Manufacturer ID: 0xc8, Chip ID: 0xd1
[    0.858402] nand: Unknown NAND 128MiB 3,3V 8-bit
[    0.863031] nand: 128MiB, SLC, page size: 2048, OOB size: 64

According to the F59L1G81MA datasheet (and Read Id documentation) C8h is
a "Maker Code" which should mean ESMT. Add it to fix above "Unknown".
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Document dmas and dma-names properties.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The sunxi NAND controller is able to pipeline ECC operations only when
operated in DMA mode, which improves a lot NAND throughput while keeping
CPU usage low.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

The 7.2 controller differs in a few area compared to its predecssor (7.1):

- NAND scrambler, which we are not using just yet
- higher ECC levels (up to 120 bits) per 1KB data blocks, also not supported yet
- up to 128B OOB

This patch adds the necessary code to support such a controller
generation and updates the Device Tree binding.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Kamal Dasu <kdasu.kdev@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Take into account transfer size limitation of SPI master.
Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Michal Suchanek <hramrach@gmail.com>
Tested-by: Michal Suchanek <hramrach@gmail.com>