Client for interacting with a Dynamic Voltage Frequency Scaling driver
dvfs_client
QNX Neutrino
ARMv7
None.
The dvfs_client utility provides a way for you to interact with a dvfsmgr-* driver.
Run this utility with no options. It will register itself under /dev/dvfs_client_#, where # is the instance number of the client. You can have a maximum of nine concurrent DVFS clients.
Use echo and cat to send commands to the DVFS driver. For example, to read the driver's status:
# cat /dev/dvfs_client_1
You can set DVFS driver's mode like this:
echo option > /dev/dvfs_client_#
The option is one of:
Change the power level like this:
echo level > /dev/dvfs_client_#
The level is one of:
To set minimum level of performance:
echo Slevel > /dev/dvfs_client_#
To unset a previously set minimum level:
echo U > /dev/dvfs_client_#
The DVFS driver responds to the device control (devctl()) messages listed below. Some commands may be valid only for a certain driver mode, as indicated.