aboutsummaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/powerpc/4xx/cpm.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/powerpc/4xx/cpm.txt')
-rw-r--r--Documentation/devicetree/bindings/powerpc/4xx/cpm.txt52
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/powerpc/4xx/cpm.txt b/Documentation/devicetree/bindings/powerpc/4xx/cpm.txt
new file mode 100644
index 00000000..ee459806
--- /dev/null
+++ b/Documentation/devicetree/bindings/powerpc/4xx/cpm.txt
@@ -0,0 +1,52 @@
+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>;
+};