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authorStefan Roese <sr@denx.de>2009-04-16 15:11:54 -0600
committerGrant Likely <grant.likely@secretlab.ca>2009-04-16 15:11:54 -0600
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parent412401029259b1ad67559cec93bcc7ee4a9551aa (diff)
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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>
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+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;
+ };
+ };