diff options
| author | Victor Gallardo <vgallardo@apm.com> | 2010-10-08 10:25:27 +0000 |
|---|---|---|
| committer | Josh Boyer <jwboyer@linux.vnet.ibm.com> | 2010-11-29 10:05:06 -0500 |
| commit | d164f6d4f9108126f69ba2963cf6fb7ef4ba9232 (patch) | |
| tree | 9f0f97180ee4f7486974c657588e8ee65074fcc2 /Documentation | |
| parent | 46f5221049bb46b0188aad6b6dfab5dbc778be22 (diff) | |
powerpc/4xx: Add suspend and idle support
Add suspend/resume support for 4xx compatible CPUs.
See /sys/power/state for available power states configured in.
Add two different idle states (idle-wait and idle-doze) controlled via sysfs.
Default is idle-wait.
cat /sys/devices/system/cpu/cpu0/idle
[wait] doze
To save additional power, use idle-doze.
echo doze > /sys/devices/system/cpu/cpu0/idle
cat /sys/devices/system/cpu/cpu0/idle
wait [doze]
Signed-off-by: Victor Gallardo <vgallardo@apm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/powerpc/dts-bindings/4xx/cpm.txt | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/powerpc/dts-bindings/4xx/cpm.txt b/Documentation/powerpc/dts-bindings/4xx/cpm.txt new file mode 100644 index 000000000000..ee459806d35e --- /dev/null +++ b/Documentation/powerpc/dts-bindings/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>; +}; |