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authorGrant Likely <grant.likely@secretlab.ca>2011-01-26 10:10:40 -0700
committerGrant Likely <grant.likely@secretlab.ca>2011-01-31 00:09:01 -0700
commitd524dac9279b6a41ffdf7ff7958c577f2e387db6 (patch)
tree294166d18a1c89c4cebb2571ea7b124876fb01ef /Documentation/devicetree/bindings/powerpc/4xx/cpm.txt
parent1bae4ce27c9c90344f23c65ea6966c50ffeae2f5 (diff)
downloadlinux-d524dac9279b6a41ffdf7ff7958c577f2e387db6.tar.bz2
dt: Move device tree documentation out of powerpc directory
The device tree is used by more than just PowerPC. Make the documentation directory available to all. v2: reorganized files while moving to create arch and driver specific directories. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
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+PPC4xx Clock Power Management (CPM) node
+
+Required properties:
+ - compatible : compatible list, currently only "ibm,cpm"
+ - dcr-access-method : "native"
+ - dcr-reg : < DCR register range >
+
+Optional properties:
+ - er-offset : All 4xx SoCs with a CPM controller have
+ one of two different order for the CPM
+ registers. Some have the CPM registers
+ in the following order (ER,FR,SR). The
+ others have them in the following order
+ (SR,ER,FR). For the second case set
+ er-offset = <1>.
+ - unused-units : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set to turn off unused
+ devices.
+ - idle-doze : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set to turn off unused
+ devices. This is usually just CPM[CPU].
+ - standby : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set on standby and
+ restored on resume.
+ - suspend : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set on suspend (mem) and
+ restored on resume. Note, for standby
+ and suspend the corresponding bits can
+ be different or the same. Usually for
+ standby only class 2 and 3 units are set.
+ However, the interface does not care.
+ If they are the same, the additional
+ power saving will be seeing if support
+ is available to put the DDR in self
+ refresh mode and any additional power
+ saving techniques for the specific SoC.
+
+Example:
+ CPM0: cpm {
+ compatible = "ibm,cpm";
+ dcr-access-method = "native";
+ dcr-reg = <0x160 0x003>;
+ er-offset = <0>;
+ unused-units = <0x00000100>;
+ idle-doze = <0x02000000>;
+ standby = <0xfeff0000>;
+ suspend = <0xfeff791d>;
+};