91 lines
3.4 KiB
Plaintext
91 lines
3.4 KiB
Plaintext
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
|
|
responsibility 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
|
|
tristate "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
|
|
tristate "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
|
|
tristate "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
|
|
tristate "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 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
|
|
select DEVFREQ_GOV_SIMPLE_ONDEMAND
|
|
select PM_OPP
|
|
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.
|
|
This does not yet operate with optimal voltages.
|
|
|
|
config ARM_EXYNOS5_BUS_DEVFREQ
|
|
tristate "ARM Exynos5250 Bus DEVFREQ Driver"
|
|
depends on SOC_EXYNOS5250
|
|
select DEVFREQ_GOV_SIMPLE_ONDEMAND
|
|
select PM_OPP
|
|
help
|
|
This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
|
|
It reads PPMU counters of memory controllers and adjusts the
|
|
operating frequencies and voltages with OPP support.
|
|
|
|
endif # PM_DEVFREQ
|