This commit slightly simplifies the code. Every parse_mtd_partitions()
caller (out of two existing ones) had to add partitions & cleanup parser
on its own. This moves that responsibility into the function.

That change also allows dropping struct mtd_partitions argument.

There is one minor behavior change caused by this cleanup. If
parse_mtd_partitions() fails to add partitions (add_mtd_partitions()
return an error) then mtd_device_parse_register() will still try to
add (register) fallback partitions. It's a real corner case affecting
one of uncommon error paths and shouldn't cause any harm.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

Type "ofpart" means that OF should be used to get partitioning info and
this driver supports "fixed-partitions" binding only. Renaming it should
lead to less confusion especially when parsers for new compatibility
strings start to appear.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

In order to properly support compatibility strings as described in the
bindings/mtd/partition.txt "ofpart" type should be treated as an
indication for looking into OF. MTD should check "compatible" property
and search for a matching parser rather than blindly trying the one
supporting "fixed-partitions".

It also means that existing "fixed-partitions" parser should get renamed
to use a more meaningful name.

This commit achievies that aim by introducing a new mtd_part_of_parse().
It works by looking for a matching parser for every string in the
"compatibility" property (starting with the most specific one).

Please note that driver-specified parsers still take a precedence. It's
assumed that driver providing a parser type has a good reason for that
(e.g. having platform data with device-specific info). Also doing
otherwise could break existing setups. The same applies to using default
parsers (including "cmdlinepart") as some overwrite DT data with cmdline
argument.

Partition parsers can now provide an of_match_table to enable
flash<-->parser matching via device tree as documented in the
mtd/partition.txt.

This support is currently limited to built-in parsers as it uses
request_module() and friends. This should be sufficient for most cases
though as compiling parsers as modules isn't a common choice.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

MTD users are no longer checking erase_info->state to determine if the
erase operation failed or succeeded. Moreover, mtd_erase_callback() is
now a NOP.

We can safely get rid of all mtd_erase_callback() calls and all
erase_info->state assignments. While at it, get rid of the
erase_info->state field, all MTD_ERASE_XXX definitions and the
mtd_erase_callback() function.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Bert Kenward <bkenward@solarflare.com>
---
Changes in v2:
- Address a few coding style issues (reported by Miquel)
- Remove comments that are no longer valid (reported by Miquel)

->fail_addr and ->addr can be updated no matter the result of
parent->_erase(), we just need to remove the code doing the same thing
in mtd_erase_callback() to avoid adjusting those fields twice.

Note that this can be done because all MTD users have been converted to
not pass an erase_info->callback() and are thus only taking the
->addr_fail and ->addr fields into account after part_erase() has
returned.

While we're at it, get rid of the erase_info->mtd field which was only
needed to let mtd_erase_callback() get the partition device back.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

None of the mtd->_erase() implementations work in an asynchronous manner,
so let's simplify MTD users that call mtd_erase(). All they need to do
is check the value returned by mtd_erase() and assume that != 0 means
failure.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>

Some of the check done in custom ->_read/write_oob() implementation are
already done by the core (in mtd_check_oob_ops()).

Suggested-by: Peter Pan <peterpansjtu@gmail.com>
[Remove redundant checks done in mtdpart.c]
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Ladislav Michl <ladis@linux-mips.org>

Some MTD sublayers/drivers are implementing ->_read/write_oob() and
provide dummy wrappers for their ->_read/write() implementations.
Let the core handle this case instead of duplicating the logic.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Tested-by: Ladislav Michl <ladis@linux-mips.org>

part_read() and part_read_oob() were counting ECC failures and
bitflips differently. Adjust part_read_oob() to mimic what is done in
part_read(). This is needed to use ->_read_oob() as a fallback when
when ->_read() is not implemented.

Note that bitflips and ECC failure accounting on MTD partitions is
broken by design, because nothing prevents concurrent accesses to the
underlying master MTD device between the moment we save the stats in a
local variable and the moment master->_read[_oob]() returns. It's not
something that can easily be fixed, so leave it like that for now.

Suggested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Ladislav Michl <ladis@linux-mips.org>

It is now unused.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Richard Weinberger <richard@nod.at>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Richard Weinberger <richard@nod.at>