treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

treewide: use cpu_relax() where appropriate ...

Instead of doing /* cpu_relax(); */ barrier(); on upstream uses of
cpu_relax(), just use the new cpu_relax() #define directly.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-imx: make sure the just created BBT is used ...

When we create a new BBT we write it to the flash, but the currently
running barebox doesn't use it yet, only after a reboot the BBT is
actually used. Call nand_default_bbt() to make sure the current barebox
also used the newly created BBT.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-imx: Create BBT automatically when necessary ...

Due to the differences of the logical page format and the raw page
format on NAND the generic nand support can't read the bad block
marker on the NAND. For this reason we have the imx_nand_bbm command
which knows about these specialities and creates a BBT. The problem
with this command is that one has to call it and experience shows
this is often forgotten. Linux will then create a BBT based on wrong
informations and the real bad blocks may be lost.

With this patch we automatically create a BBT when none is found and
make the command unnecssary.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-imx: do not use blocks reserved for BBT ...

Due to the differences of the logical page format and the raw page
format on NAND the generic nand support can't read the bad block marker
on the NAND. For this reason we cleared the NAND_BBT_CREATE flag and
have the imx_nand_bbm command to create a BBT if none is found in the
flash. We have also cleared the NAND_BBT_WRITE flag which causes
problems.  Normally a BBT occupies two blocks in NAND, but to have some
space for the BBT when one of these becomes bad we normally reserve 4
blocks for the BBT. In case we want to write the BBT to flash we have to
reserve them from being written to by general NAND operations. In case
we don't ever write to the BBT, as indicated by a cleared NAND_BBT_WRITE
flag, the reserved blocks can be used by the general NAND operations.
This way it happens that barebox uses the reserved blocks for data
storage, but Linux (which has NAND_BBT_WRITE set) can't read any data
from it.  This results in corrupted UBI images.

It's not necessary to clear the NAND_BBT_WRITE flag, all we really have
to do is to prevent the BBT layer from creating a new BBT. For this it's
enough to clear the NAND_BBT_CREATE flag.

Fixes: 545453ddae ("mtd: nand: Add command to generate a flash BBT")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: don't call BBT functions if BBT support isn't built ...

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: nand_omap_gpmc: Fix mtd_info usage ...

The mtd_info has not been set correctly in the omap gpmc probe.
Remove the mtd_info in the private struct like it has been done in
other nand drivers. And update the driver accordingly.

Fixes: 76b6f74c5397 ("mtd: nand: Embed struct mtd_info into struct nand_chip")

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/omap'

mtd: nand: gpmc: Add BCH16 support ...

This adds support for BCH16 ECC encoding. The support is mostly taken
from Linux-5.3-rc6. One major change is the different wrap mode used.
The Kernel uses wrapmode 1, which means "pass all data through the BCH
engine". Still the Kernel has to skip the OOB marker which is done by
reading all user data, then use NAND_CMD_RNDOUT to position right
behind the OOB marker and then read the ECC data. Instead of doing this
we use wrap mode 4 which allows us to bypass the OOB marker from the
BCH engine automatically. This explains

bch_wrapmode = 1, eccsize0 = 0, eccsize1 = 52 vs.
bch_wrapmode = 4, eccsize0 = 4, eccsize1 = 52

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: gpmc: Add support for ELM ...

This adds support for the ELM (Error Location Module) found on
not-too-old OMAP SoCs. The driver has been taken from Linux-5.3-rc6
with interrupt support removed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: Embed struct mtd_info into struct nand_chip ...

Similar to what is done in the Kernel. In the Kernel we have a struct
nand_device embedded into struct nand_chip and the nand_device has an
mtd_info embedded into it. Until we have struct nand_device we embed
mtd_info directly into the nand_chip.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: denali: Add variables for mtd_info and nand_chip ...

Accessing the mtd_info from the nand_chip will change in the next patch,
so instead of accessing it each time when used create a variable for
mtd_info to keep the next patch smaller.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: Add and use static inline wrapper for getting nand_chip from mtd ...

All drivers in tree use mtd->priv for the nand_chip. Add and use a static
inline wrapper mtd_to_nand() which we already have in the kernel for
getting the nand_chip from the mtd_info struct. Next step would be to
embed a struct mtd_info into struct nand_chip.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/mtd-gpmi-nand'

mtd: nand-mxs: Make ecc strength configurable via device tree ...

According to the binding doc the mxs NAND driver supports the
"nand-ecc-strength" and "nand-ecc-step-size" options. This adds support
for these options to the driver. The "nand-ecc-step-size" is not
really configurable, the only accepted value is 512 so this is merely
to sanity check that there's nothing specified that we can't yet
support.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: Add function to parse device tree properties ...

This adds nand_of_parse_node() which can be used to parse generic
NAND device properties. Not very complete yet, but it's a start.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-mxs: inline only once used function ...

mxs_nand_ecc_size_in_bits() is used only once and is simple enough to
be inlined.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-mxs: pass mtd_info to mxs_nand_get_mark_offset() ...

struct mtd_info * contains everything mxs_nand_get_mark_offset() needs,
so pass this pointer rather than several integer arguments.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-mxs: change API between NAND driver and fcb code ...

The imx-bbu-nand-fcb update handler code calls into the NAND driver
to get the ecc strength and bad block marker position. Change the
API so that only a single function is necessary and not three functions.
Also in future the ecc strength will be configurable via device tree.
This means static parameters like page size / oob size are no longer
enough to calculate the ecc strength and so we store a pointer to our
mtd_info struct in a static global variable.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-mxs: Make locally used variable static ...

fake_ecc_layout is only used in the mxs nand driver, so make it static.
Also it's not necessary to zero the structure.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-mxs: calculate ecc_strength only once ...

Instead of calculating the ecc strength multiple times with each page
read just do it once and store the result in chip->ecc.strength.

While at it also store the correct value in chip->ecc.bytes instead of
writing a bogus value into it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand-mxs: consistently rename struct nand_chip * to "chip" ...

The struct nand_chip * is sometimes named "nand" and sometimes "chip".
For consistency name it "chip" throughout the driver.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: Add ecc parameters as device parameters ...

The ecc strength/bytes/size values are useful informations sometimes,
add them as device parameters.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

nand: nand_mxs: Do not zero out DMA coherent memory ...

Memory returned by dma_alloc_coherent() should already be zeroed
out, so there's no need to do this explicitly.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: devfs: Change .lseek callbacks to return 'int' ...

Returning requested offset from .lseek() callback doesn't really give
us any new information while bringing unnecessary
complications. Change all .lseek() types (both in struct struct
cdev_operations and in struct fs_driver_d) to return 'int' and adjust
the rest of the codebase accordingly.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Revert "mtd: nand: Kill the chip->scan_bbt() hook" ...

This reverts commit 95ce697.

Merge branch 'for-next/mtd'

mtd: nand: omap: unbreak BCH8 support ...

We now tell the NAND layer that we have subpages with 512 bytes each.
This means the calculate_ecc / correct hooks are also called for each
subpage which means we cannot iterate over subpages in the calculate_ecc
callback.

Implement this correctly by removing the loop over subpages in the
calculate_ecc callback and by implementing a read_page callback.

With this the bch8_hw and bch8_hw_romcode were tested on AM335x, OMAP4
and AM3517. Number of bitflips is correctly reported as tested with the
nand_bitflip tool.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

With fix from Teresa:

Using BCH rom code mode we start calculating with GPMC_BCH_RESULTx_1.
Fix offset for correct error correction.

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: nand_base: Fix compile warning if CONFIG_MTD_WRITE is not enabled ...

drivers/mtd/nand/nand_base.c:337:12: warning: 'nand_default_block_markbad'
defined but not used [-Wunused-function]

Add __maybe_unused again to silence warning when CONFIG_MTD_WRITE is not enabled.

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mtd: nand: detect OOB size for Toshiba 24nm raw SLC ...

Linux commit 60c673824561.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>