drivers/devfreq/Kconfig

   1 menuconfig PM_DEVFREQ
   2         bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
   3         help
   4           A device may have a list of frequencies and voltages available.
   5           devfreq, a generic DVFS framework can be registered for a device
   6           in order to let the governor provided to devfreq choose an
   7           operating frequency based on the device driver's policy.
   8
   9           Each device may have its own governor and policy. Devfreq can
  10           reevaluate the device state periodically and/or based on the
  11           notification to "nb", a notifier block, of devfreq.
  12
  13           Like some CPUs with CPUfreq, a device may have multiple clocks.
  14           However, because the clock frequencies of a single device are
  15           determined by the single device's state, an instance of devfreq
  16           is attached to a single device and returns a "representative"
  17           clock frequency of the device, which is also attached
  18           to a device by 1-to-1. The device registering devfreq takes the
  19           responsibility to "interpret" the representative frequency and
  20           to set its every clock accordingly with the "target" callback
  21           given to devfreq.
  22
  23           When OPP is used with the devfreq device, it is recommended to
  24           register devfreq's nb to the OPP's notifier head.  If OPP is
  25           used with the devfreq device, you may use OPP helper
  26           functions defined in devfreq.h.
  27
  28 if PM_DEVFREQ
  29
  30 comment "DEVFREQ Governors"
  31
  32 config DEVFREQ_GOV_SIMPLE_ONDEMAND
  33         tristate "Simple Ondemand"
  34         help
  35           Chooses frequency based on the recent load on the device. Works
  36           similar as ONDEMAND governor of CPUFREQ does. A device with
  37           Simple-Ondemand should be able to provide busy/total counter
  38           values that imply the usage rate. A device may provide tuned
  39           values to the governor with data field at devfreq_add_device().
  40
  41 config DEVFREQ_GOV_PERFORMANCE
  42         tristate "Performance"
  43         help
  44           Sets the frequency at the maximum available frequency.
  45           This governor always returns UINT_MAX as frequency so that
  46           the DEVFREQ framework returns the highest frequency available
  47           at any time.
  48
  49 config DEVFREQ_GOV_POWERSAVE
  50         tristate "Powersave"
  51         help
  52           Sets the frequency at the minimum available frequency.
  53           This governor always returns 0 as frequency so that
  54           the DEVFREQ framework returns the lowest frequency available
  55           at any time.
  56
  57 config DEVFREQ_GOV_USERSPACE
  58         tristate "Userspace"
  59         help
  60           Sets the frequency at the user specified one.
  61           This governor returns the user configured frequency if there
  62           has been an input to /sys/devices/.../power/devfreq_set_freq.
  63           Otherwise, the governor does not change the frequnecy
  64           given at the initialization.
  65
  66 comment "DEVFREQ Drivers"
  67
  68 config ARM_EXYNOS4_BUS_DEVFREQ
  69         bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
  70         depends on (CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
  71         select DEVFREQ_GOV_SIMPLE_ONDEMAND
  72         select PM_OPP
  73         help
  74           This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
  75           and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
  76           It reads PPMU counters of memory controllers and adjusts
  77           the operating frequencies and voltages with OPP support.
  78           This does not yet operate with optimal voltages.
  79
  80 config ARM_EXYNOS5_BUS_DEVFREQ
  81         tristate "ARM Exynos5250 Bus DEVFREQ Driver"
  82         depends on SOC_EXYNOS5250
  83         select DEVFREQ_GOV_SIMPLE_ONDEMAND
  84         select PM_OPP
  85         help
  86           This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
  87           It reads PPMU counters of memory controllers and adjusts the
  88           operating frequencies and voltages with OPP support.
  89
  90 endif # PM_DEVFREQ