| config ARCH_HAS_DEVFREQ |
| bool |
| depends on ARCH_HAS_OPP |
| help |
| Denotes that the architecture supports DEVFREQ. If the architecture |
| supports multiple OPP entries per device and the frequency of the |
| devices with OPPs may be altered dynamically, the architecture |
| supports DEVFREQ. |
| |
| menuconfig PM_DEVFREQ |
| bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" |
| depends on PM_OPP && ARCH_HAS_DEVFREQ |
| help |
| With OPP support, a device may have a list of frequencies and |
| voltages available. DEVFREQ, a generic DVFS framework can be |
| registered for a device with OPP support in order to let the |
| governor provided to DEVFREQ choose an operating frequency |
| based on the OPP's list and the policy given with DEVFREQ. |
| |
| Each device may have its own governor and policy. DEVFREQ can |
| reevaluate the device state periodically and/or based on the |
| OPP list changes (each frequency/voltage pair in OPP may be |
| disabled or enabled). |
| |
| Like some CPUs with CPUFREQ, a device may have multiple clocks. |
| However, because the clock frequencies of a single device are |
| determined by the single device's state, an instance of DEVFREQ |
| is attached to a single device and returns a "representative" |
| clock frequency from the OPP of the device, which is also attached |
| to a device by 1-to-1. The device registering DEVFREQ takes the |
| responsiblity to "interpret" the frequency listed in OPP and |
| to set its every clock accordingly with the "target" callback |
| given to DEVFREQ. |
| |
| if PM_DEVFREQ |
| |
| comment "DEVFREQ Governors" |
| |
| config DEVFREQ_GOV_SIMPLE_ONDEMAND |
| bool "Simple Ondemand" |
| help |
| Chooses frequency based on the recent load on the device. Works |
| similar as ONDEMAND governor of CPUFREQ does. A device with |
| Simple-Ondemand should be able to provide busy/total counter |
| values that imply the usage rate. A device may provide tuned |
| values to the governor with data field at devfreq_add_device(). |
| |
| config DEVFREQ_GOV_PERFORMANCE |
| bool "Performance" |
| help |
| Sets the frequency at the maximum available frequency. |
| This governor always returns UINT_MAX as frequency so that |
| the DEVFREQ framework returns the highest frequency available |
| at any time. |
| |
| config DEVFREQ_GOV_POWERSAVE |
| bool "Powersave" |
| help |
| Sets the frequency at the minimum available frequency. |
| This governor always returns 0 as frequency so that |
| the DEVFREQ framework returns the lowest frequency available |
| at any time. |
| |
| config DEVFREQ_GOV_USERSPACE |
| bool "Userspace" |
| help |
| Sets the frequency at the user specified one. |
| This governor returns the user configured frequency if there |
| has been an input to /sys/devices/.../power/devfreq_set_freq. |
| Otherwise, the governor does not change the frequnecy |
| given at the initialization. |
| |
| comment "DEVFREQ Drivers" |
| |
| endif # PM_DEVFREQ |
