kernel/linux.git/include/linux/mtd/partitions.h, branch v6.19.11

Revert "mtd: core: always create master device"

2025-06-18T09:18:23+00:00

The idea behind this patch was to always let a "master" mtd device available to anchor runtime PM. Historically, there was no mtd device representing the whole storage as soon as partitions were coming into play. The introduction of CONFIG_MTD_PARTITIONED_MASTER allowed to keep this "master" device, but was not enabled by default to avoid breaking existing users (otherwise the mtd device numbering would be totally messed up with an off by 1, at least). The approach of adding an mtd_master class on top of partitioned mtd devices is breaking the mtd core in many creative ways, so better think again this approach and revert the faulty changes for now. This reverts commit 0aa7b390fc40a871267a2328bbbefca8b37ad307. Fixes: 0aa7b390fc40 ("mtd: core: always create master device") Tested-by: Guenter Roeck Acked-by: Guenter Roeck Signed-off-by: Miquel Raynal

mtd: core: always create master device

2025-05-13T07:33:57+00:00

Create master device without partition when CONFIG_MTD_PARTITIONED_MASTER flag is unset. This streamlines device tree and allows to anchor runtime power management on master device in all cases. Signed-off-by: Alexander Usyskin Signed-off-by: Miquel Raynal

mtd: Add support for emulated SLC mode on MLC NANDs

2020-05-11T07:51:41+00:00

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

mtd: implement proper partition handling

2020-03-11T13:49:30+00:00

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 Link: https://lore.kernel.org/linux-mtd/20200114090952.11232-1-miquel.raynal@bootlin.com

mtd: partitions: add of_match_table parser matching for the "ofpart" type

2018-03-27T07:10:48+00:00

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 Signed-off-by: Rafał Miłecki Tested-by: Peter Rosin Reviewed-by: Richard Weinberger Signed-off-by: Boris Brezillon

mtd: partitions: add support for partition parsers

2017-06-22T20:13:09+00:00

Some devices have partitions that are kind of containers with extra subpartitions / volumes instead of e.g. a simple filesystem data. To support such cases we need to first create normal flash device partitions and then take care of these special ones. It's very common case for home routers. Depending on the vendor there are formats like TRX, Seama, TP-Link, WRGG & more. All of them are used to embed few partitions into a single one / single firmware file. Ideally all vendors would use some well documented / standardized format like UBI (and some probably start doing so), but there are still countless devices on the market using these poor vendor specific formats. This patch extends MTD subsystem by allowing to specify list of parsers that should be tried for a given partition. Supporting such poor formats is highly unlikely to be the top priority so these changes try to minimize maintenance cost to the minimum. It reuses existing code for these new parsers and just adds a one property and one new function. This implementation requires setting partition parsers in a flash parser. A proper change of bcm47xxpart will follow and in the future we will hopefully also find a solution for doing it with ofpart ("fixed-partitions"). Signed-off-by: Rafał Miłecki Signed-off-by: Brian Norris

mtd: Add partition device node to mtd partition devices

2017-02-10T03:19:25+00:00

The user visible change here is that mtd partitions get an of_node link in sysfs. Signed-off-by: Sascha Hauer Signed-off-by: Uwe Kleine-König Signed-off-by: Brian Norris

mtd: partitions: support a cleanup callback for parsers

2015-12-09T22:57:44+00:00

If partition parsers need to clean up their resources, we shouldn't assume that all memory will fit in a single kmalloc() that the caller can kfree(). We should allow the parser to provide a proper cleanup routine. Note that this means we need to keep a hold on the parser's module for a bit longer, and release it later with mtd_part_parser_put(). Alongside this, define a default callback that we'll automatically use if the parser doesn't provide one, so we can still retain the old behavior. Signed-off-by: Brian Norris Reviewed-by: Boris Brezillon

mtd: partitions: pass around 'mtd_partitions' wrapper struct

2015-12-09T18:22:09+00:00

For some of the core partitioning code, it helps to keep info about the parsed partition (and who parsed them) together in one place. Signed-off-by: Brian Norris

mtd: partitions: make parsers return 'const' partition arrays

2015-12-09T18:21:57+00:00

We only want to modify these arrays inside the parser "drivers", so the drivers should construct them however they like, then return them as immutable arrays. This will make other refactorings easier. Signed-off-by: Brian Norris Reviewed-by: Boris Brezillon