[linux-2.6-block.git] / drivers / devfreq / Kconfig

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 Drivers"

endif # PM_DEVFREQ
Commit	Line	Data
a3c98b8b MH	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 Drivers"
	38
	39	endif # PM_DEVFREQ