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path: root/drivers/devfreq/Kconfig
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menuconfig PM_DEVFREQ
	bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
	help
	  A device may have a list of frequencies and voltages available.
	  devfreq, a generic DVFS framework can be registered for a device
	  in order to let the governor provided to devfreq choose an
	  operating frequency based on the device driver's policy.

	  Each device may have its own governor and policy. Devfreq can
	  reevaluate the device state periodically and/or based on the
	  notification to "nb", a notifier block, of devfreq.

	  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 of the device, which is also attached
	  to a device by 1-to-1. The device registering devfreq takes the
	  responsiblity to "interpret" the representative frequency and
	  to set its every clock accordingly with the "target" callback
	  given to devfreq.

	  When OPP is used with the devfreq device, it is recommended to
	  register devfreq's nb to the OPP's notifier head.  If OPP is
	  used with the devfreq device, you may use OPP helper
	  functions defined in devfreq.h.

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"

config ARM_EXYNOS4_BUS_DEVFREQ
	bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
	depends on CPU_EXYNOS4210 || CPU_EXYNOS4212 || CPU_EXYNOS4412
	select ARCH_HAS_OPP
	select DEVFREQ_GOV_SIMPLE_ONDEMAND
	help
	  This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
	  and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
	  It reads PPMU counters of memory controllers and adjusts
	  the operating frequencies and voltages with OPP support.
	  To operate with optimal voltages, ASV support is required
	  (CONFIG_EXYNOS_ASV).

endif # PM_DEVFREQ