mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 23:23:55 +08:00
d524dac927
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>
53 lines
1.8 KiB
Plaintext
53 lines
1.8 KiB
Plaintext
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>;
|
|
};
|