drivers/devfreq/Kconfig

   1 config ARCH_HAS_DEVFREQ
   2         bool
   3         depends on ARCH_HAS_OPP
   4         help
   5           Denotes that the architecture supports DEVFREQ. If the architecture
   6           supports multiple OPP entries per device and the frequency of the
   7           devices with OPPs may be altered dynamically, the architecture
   8           supports DEVFREQ.
   9
  10 menuconfig PM_DEVFREQ
  11         bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
  12         depends on PM_OPP && ARCH_HAS_DEVFREQ
  13         help
  14           With OPP support, a device may have a list of frequencies and
  15           voltages available. DEVFREQ, a generic DVFS framework can be
  16           registered for a device with OPP support in order to let the
  17           governor provided to DEVFREQ choose an operating frequency
  18           based on the OPP's list and the policy given with DEVFREQ.
  19
  20           Each device may have its own governor and policy. DEVFREQ can
  21           reevaluate the device state periodically and/or based on the
  22           OPP list changes (each frequency/voltage pair in OPP may be
  23           disabled or enabled).
  24
  25           Like some CPUs with CPUFREQ, a device may have multiple clocks.
  26           However, because the clock frequencies of a single device are
  27           determined by the single device's state, an instance of DEVFREQ
  28           is attached to a single device and returns a "representative"
  29           clock frequency from the OPP of the device, which is also attached
  30           to a device by 1-to-1. The device registering DEVFREQ takes the
  31           responsiblity to "interpret" the frequency listed in OPP and
  32           to set its every clock accordingly with the "target" callback
  33           given to DEVFREQ.
  34
  35 if PM_DEVFREQ
  36
  37 comment "DEVFREQ Governors"
  38
  39 config DEVFREQ_GOV_SIMPLE_ONDEMAND
  40         bool "Simple Ondemand"
  41         help
  42           Chooses frequency based on the recent load on the device. Works
  43           similar as ONDEMAND governor of CPUFREQ does. A device with
  44           Simple-Ondemand should be able to provide busy/total counter
  45           values that imply the usage rate. A device may provide tuned
  46           values to the governor with data field at devfreq_add_device().
  47
  48 config DEVFREQ_GOV_PERFORMANCE
  49         bool "Performance"
  50         help
  51           Sets the frequency at the maximum available frequency.
  52           This governor always returns UINT_MAX as frequency so that
  53           the DEVFREQ framework returns the highest frequency available
  54           at any time.
  55
  56 config DEVFREQ_GOV_POWERSAVE
  57         bool "Powersave"
  58         help
  59           Sets the frequency at the minimum available frequency.
  60           This governor always returns 0 as frequency so that
  61           the DEVFREQ framework returns the lowest frequency available
  62           at any time.
  63
  64 config DEVFREQ_GOV_USERSPACE
  65         bool "Userspace"
  66         help
  67           Sets the frequency at the user specified one.
  68           This governor returns the user configured frequency if there
  69           has been an input to /sys/devices/.../power/devfreq_set_freq.
  70           Otherwise, the governor does not change the frequnecy
  71           given at the initialization.
  72
  73 comment "DEVFREQ Drivers"
  74
  75 endif # PM_DEVFREQ