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-rw-r--r--Documentation/powerpc/booting-without-of.txt40
1 files changed, 36 insertions, 4 deletions
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index c36dcd2fbdc..ce5d67f5cb5 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -1861,9 +1861,7 @@ platforms are moved over to use the flattened-device-tree model.
Properties:
- compatible : "fsl,cpm1", "fsl,cpm2", or "fsl,qe".
- - reg : The first resource is a 48-byte region beginning with
- CPCR. The second is the available general-purpose
- DPRAM.
+ - reg : A 48-byte region beginning with CPCR.
Example:
cpm@119c0 {
@@ -1871,7 +1869,7 @@ platforms are moved over to use the flattened-device-tree model.
#size-cells = <1>;
#interrupt-cells = <2>;
compatible = "fsl,mpc8272-cpm", "fsl,cpm2";
- reg = <119c0 30 0 2000>;
+ reg = <119c0 30>;
}
ii) Properties common to mulitple CPM/QE devices
@@ -2017,6 +2015,40 @@ platforms are moved over to use the flattened-device-tree model.
fsl,cpm-command = <2e600000>;
};
+ viii) Multi-User RAM (MURAM)
+
+ The multi-user/dual-ported RAM is expressed as a bus under the CPM node.
+
+ Ranges must be set up subject to the following restrictions:
+
+ - Children's reg nodes must be offsets from the start of all muram, even
+ if the user-data area does not begin at zero.
+ - If multiple range entries are used, the difference between the parent
+ address and the child address must be the same in all, so that a single
+ mapping can cover them all while maintaining the ability to determine
+ CPM-side offsets with pointer subtraction. It is recommended that
+ multiple range entries not be used.
+ - A child address of zero must be translatable, even if no reg resources
+ contain it.
+
+ A child "data" node must exist, compatible with "fsl,cpm-muram-data", to
+ indicate the portion of muram that is usable by the OS for arbitrary
+ purposes. The data node may have an arbitrary number of reg resources,
+ all of which contribute to the allocatable muram pool.
+
+ Example, based on mpc8272:
+
+ muram@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0 10000>;
+
+ data@0 {
+ compatible = "fsl,cpm-muram-data";
+ reg = <0 2000 9800 800>;
+ };
+ };
+
m) Chipselect/Local Bus
Properties: