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author | Stefan Roese <sr@denx.de> | 2009-04-16 15:11:54 -0600 |
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committer | Grant Likely <grant.likely@secretlab.ca> | 2009-04-16 15:11:54 -0600 |
commit | efcc2da3fd148c9acb7d7cf1d9800e0649f950fc (patch) | |
tree | 99c93da3639a22d3ac487c575425f7a0c46d2826 /Documentation/powerpc/dts-bindings/mtd-physmap.txt | |
parent | 412401029259b1ad67559cec93bcc7ee4a9551aa (diff) | |
download | linux-efcc2da3fd148c9acb7d7cf1d9800e0649f950fc.tar.gz linux-efcc2da3fd148c9acb7d7cf1d9800e0649f950fc.tar.bz2 linux-efcc2da3fd148c9acb7d7cf1d9800e0649f950fc.zip |
powerpc/of-device-tree: Factor MTD physmap bindings out of booting-without-of
It's easier to find bindings descriptions in separate files. So factor
out the MTD physmap bindings into a separate file to not clutter
booting-without-of.txt more.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'Documentation/powerpc/dts-bindings/mtd-physmap.txt')
-rw-r--r-- | Documentation/powerpc/dts-bindings/mtd-physmap.txt | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/powerpc/dts-bindings/mtd-physmap.txt b/Documentation/powerpc/dts-bindings/mtd-physmap.txt new file mode 100644 index 000000000000..cd474f9aef39 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/mtd-physmap.txt @@ -0,0 +1,63 @@ +CFI or JEDEC memory-mapped NOR flash + +Flash chips (Memory Technology Devices) are often used for solid state +file systems on embedded devices. + + - compatible : should contain the specific model of flash chip(s) + used, if known, followed by either "cfi-flash" or "jedec-flash" + - reg : Address range of the flash chip + - bank-width : Width (in bytes) of the flash bank. Equal to the + device width times the number of interleaved chips. + - device-width : (optional) Width of a single flash chip. If + omitted, assumed to be equal to 'bank-width'. + - #address-cells, #size-cells : Must be present if the flash has + sub-nodes representing partitions (see below). In this case + both #address-cells and #size-cells must be equal to 1. + +For JEDEC compatible devices, the following additional properties +are defined: + + - vendor-id : Contains the flash chip's vendor id (1 byte). + - device-id : Contains the flash chip's device id (1 byte). + +In addition to the information on the flash bank itself, the +device tree may optionally contain additional information +describing partitions of the flash address space. This can be +used on platforms which have strong conventions about which +portions of the flash are used for what purposes, but which don't +use an on-flash partition table such as RedBoot. + +Each partition is represented as a sub-node of the flash device. +Each node's name represents the name of the corresponding +partition of the flash device. + +Flash partitions + - reg : The partition's offset and size within the flash bank. + - label : (optional) The label / name for this flash partition. + If omitted, the label is taken from the node name (excluding + the unit address). + - read-only : (optional) This parameter, if present, is a hint to + Linux that this flash partition should only be mounted + read-only. This is usually used for flash partitions + containing early-boot firmware images or data which should not + be clobbered. + +Example: + + flash@ff000000 { + compatible = "amd,am29lv128ml", "cfi-flash"; + reg = <ff000000 01000000>; + bank-width = <4>; + device-width = <1>; + #address-cells = <1>; + #size-cells = <1>; + fs@0 { + label = "fs"; + reg = <0 f80000>; + }; + firmware@f80000 { + label ="firmware"; + reg = <f80000 80000>; + read-only; + }; + }; |