partid and partname debugfs files were used just by SPI NOR, but they were
replaced by sysfs entries. Since these debugfs files are no longer used in
mtd, remove dead code. The directory is kept as it is used by nandsim,
mtdswap and docg3.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220225144656.634682-1-tudor.ambarus@microchip.com

Reduce the number of exported symbols by replacing:
- mtd_expert_analysis_warning (the error string)
- mtd_expert_analysis_mode (the boolean)
with a single helper:
- mtd_check_expert_analysis_mode

Calling this helper will both check/return the content of the internal
boolean -which is not exported anymore- and as well conditionally
WARN_ONCE() the user, like it was done before.

While on this function, make the error string local to the helper and
set it const. Only export this helper when CONFIG_DEBUG_FS is defined to
limit the growth of the Linux kernel size only for a debug feature on
production kernels.

Mechanically update all the consumers.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220128113414.1121924-1-miquel.raynal@bootlin.com

When developping NAND controller drivers or when debugging filesystem
corruptions, it is quite common to need hacking locally into the
MTD/NAND core in order to get access to the content of the bad
blocks. Instead of having multiple implementations out there let's
provide a simple yet effective specific MTD-wide debugfs entry to fully
disable these checks on purpose.

A warning is added to inform the user when this mode gets enabled.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211118114659.1282855-1-miquel.raynal@bootlin.com

All uses of MTD_MAX_{OOBFREE,ECCPOS}_ENTRIES_LARGE have been removed as
commit ef5eeea6e911 ("mtd: nand: brcm: switch to mtd_ooblayout_ops") and
commit aab616e31d1c ("mtd: kill the nand_ecclayout struct") replaced
struct nand_ecclayout by the new mtd_ooblayout_ops interface. Remove
these two macros therefore.

Reported-by: Yi Yang <yiyang13@huawei.com>
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210830083356.31702-1-gongruiqi1@huawei.com

Flash OTP regions can already be read via user space. Some boards have
their serial number or MAC addresses stored in the OTP regions. Add
support for them being a (read-only) nvmem provider.

The API to read the OTP data is already in place. It distinguishes
between factory and user OTP, thus there are up to two different
providers.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210424110608.15748-6-michael@walle.cc

The write buffer comes from user and should be const.
Constify write buffer in mtd core and across all _write_user_prot_reg()
users. cfi_cmdset_{0001, 0002} and onenand_base will pay the cost of an
explicit cast to discard the const qualifier since the beginning, since
they are using an otp_op_t function prototype that is used for both reads
and writes. mtd_dataflash and SPI NOR will benefit of the const buffer
because they are using different paths for writes and reads.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210403060931.7119-1-tudor.ambarus@microchip.com

This may sound like a contradiction but some SPI-NOR flashes really
support erasing their OTP region until it is finally locked. Having the
possibility to erase an OTP region might come in handy during
development.

The ioctl argument follows the OTPLOCK style.

Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210303201819.2752-1-michael@walle.cc

Get rid of central chrdev MTD lock, which prevents simultaneous operations
on completely independent physical MTD chips. Replace it with newly
introduced per-master mutex.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210217211845.43364-2-alexander.sverdlin@nokia.com

MLC NANDs can be made a bit more reliable if we only program the lower
page of each pair. At least, this solves the paired-pages corruption
issue.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200503155341.16712-5-miquel.raynal@bootlin.com

Instead of collecting partitions in a flat list, create a hierarchy
within the mtd_info structure: use a partitions list to keep track of
the partitions of an MTD device (which might be itself a partition of
another MTD device), a pointer to the parent device (NULL when the MTD
device is the root one, not a partition).

By also saving directly in mtd_info the offset of the partition, we
can get rid of the mtd_part structure.

While at it, be consistent in the naming of the mtd_info structures to
ease the understanding of the new hierarchy: these structures are
usually called 'mtd', unless there are multiple instances of the same
structure. In this case, there is usually a parent/child bound so we
will call them 'parent' and 'child'.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200114090952.11232-1-miquel.raynal@bootlin.com