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author | Brian Norris <computersforpeace@gmail.com> | 2017-05-23 08:30:19 +0300 |
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committer | Brian Norris <computersforpeace@gmail.com> | 2017-06-20 22:59:11 +0300 |
commit | df1d178879f53d7f790d4bc372aa0fc5d5423328 (patch) | |
tree | 93500a468a58d1b4d57c819eb9827225013cc461 /Documentation/devicetree/bindings/mtd | |
parent | 1eeef2d7483a7e3f8d2dd2a5b9939b3b814dc549 (diff) | |
download | linux-df1d178879f53d7f790d4bc372aa0fc5d5423328.tar.xz |
dt-bindings: mtd: make partitions doc a bit more generic
Currently the only documented partitioning is "fixed-partitions" but
there are more methods in use that we may want to support in the future.
Mention them and make it clear Fixed Partitions are just a single case.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'Documentation/devicetree/bindings/mtd')
-rw-r--r-- | Documentation/devicetree/bindings/mtd/partition.txt | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/mtd/partition.txt b/Documentation/devicetree/bindings/mtd/partition.txt index 81a224da63be..36f3b769a626 100644 --- a/Documentation/devicetree/bindings/mtd/partition.txt +++ b/Documentation/devicetree/bindings/mtd/partition.txt @@ -1,29 +1,49 @@ -Representing flash partitions in devicetree +Flash partitions in device tree +=============================== -Partitions can be represented by sub-nodes of an mtd device. This can be used +Flash devices can be partitioned into one or more functional ranges (e.g. "boot +code", "nvram", "kernel"). + +Different devices may be partitioned in a different ways. Some may use a fixed +flash layout set at production time. Some may use on-flash table that describes +the geometry and naming/purpose of each functional region. It is also possible +to see these methods mixed. + +To assist system software in locating partitions, we allow describing which +method is used for a given flash device. To describe the method there should be +a subnode of the flash device that is named 'partitions'. It must have a +'compatible' property, which is used to identify the method to use. + +We currently only document a binding for fixed layouts. + + +Fixed Partitions +================ + +Partitions can be represented by sub-nodes of a flash device. This can be used on platforms which have strong conventions about which portions of a flash are used for what purposes, but which don't use an on-flash partition table such as RedBoot. -The partition table should be a subnode of the mtd node and should be named +The partition table should be a subnode of the flash node and should be named 'partitions'. This node should have the following property: - compatible : (required) must be "fixed-partitions" Partitions are then defined in subnodes of the partitions node. -For backwards compatibility partitions as direct subnodes of the mtd device are +For backwards compatibility partitions as direct subnodes of the flash device are supported. This use is discouraged. NOTE: also for backwards compatibility, direct subnodes that have a compatible string are not considered partitions, as they may be used for other bindings. #address-cells & #size-cells must both be present in the partitions subnode of the -mtd device. There are two valid values for both: +flash device. There are two valid values for both: <1>: for partitions that require a single 32-bit cell to represent their size/address (aka the value is below 4 GiB) <2>: for partitions that require two 32-bit cells to represent their size/address (aka the value is 4 GiB or greater). Required properties: -- reg : The partition's offset and size within the mtd bank. +- reg : The partition's offset and size within the flash Optional properties: - label : The label / name for this partition. If omitted, the label is taken |