See the page for the specific family of boards you are using for information on the kernel source, DPM patches, and DPM utilities to use.
Run the dpm-setup-board script to setup example DPM "operating points" (consistent sets of values for platform power parameters) and "policies" (mappings of "operating states" such as idle or running a low-priority task to operating points). The example operating points and policies may be customized for your board or for your system requirements. In some cases more information on customizing operating points appears on the page for the specific board family.
The script also activates one of the sample policies.
Check operation with:
$ mount -t sysfs sysfs /sys (if not already) $ cat /sys/dpm/control
The string "enabled" should appear, followed by the names of the current power policy, operating state (usually "task" at the time "cat" runs), and the name of the operating point that the "task" operating state maps to.
The statistics given by the former /proc interface are being reworked for a future version of the sysfs interface; if you have the DPM /proc interface configured then "cat /proc/driver/dpm/stats" will show information on the number of entries to each operating state and the time spent in each operating state (as well as the operating point mapped for the operating state in the current policy).