104 lines
3.9 KiB
Plaintext
104 lines
3.9 KiB
Plaintext
menuconfig PM_DEVFREQ
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bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
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select SRCU
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help
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A device may have a list of frequencies and voltages available.
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devfreq, a generic DVFS framework can be registered for a device
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in order to let the governor provided to devfreq choose an
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operating frequency based on the device driver's policy.
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Each device may have its own governor and policy. Devfreq can
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reevaluate the device state periodically and/or based on the
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notification to "nb", a notifier block, of devfreq.
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Like some CPUs with CPUfreq, a device may have multiple clocks.
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However, because the clock frequencies of a single device are
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determined by the single device's state, an instance of devfreq
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is attached to a single device and returns a "representative"
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clock frequency of the device, which is also attached
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to a device by 1-to-1. The device registering devfreq takes the
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responsibility to "interpret" the representative frequency and
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to set its every clock accordingly with the "target" callback
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given to devfreq.
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When OPP is used with the devfreq device, it is recommended to
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register devfreq's nb to the OPP's notifier head. If OPP is
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used with the devfreq device, you may use OPP helper
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functions defined in devfreq.h.
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if PM_DEVFREQ
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comment "DEVFREQ Governors"
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config DEVFREQ_GOV_SIMPLE_ONDEMAND
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tristate "Simple Ondemand"
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help
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Chooses frequency based on the recent load on the device. Works
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similar as ONDEMAND governor of CPUFREQ does. A device with
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Simple-Ondemand should be able to provide busy/total counter
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values that imply the usage rate. A device may provide tuned
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values to the governor with data field at devfreq_add_device().
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config DEVFREQ_GOV_PERFORMANCE
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tristate "Performance"
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help
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Sets the frequency at the maximum available frequency.
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This governor always returns UINT_MAX as frequency so that
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the DEVFREQ framework returns the highest frequency available
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at any time.
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config DEVFREQ_GOV_POWERSAVE
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tristate "Powersave"
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help
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Sets the frequency at the minimum available frequency.
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This governor always returns 0 as frequency so that
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the DEVFREQ framework returns the lowest frequency available
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at any time.
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config DEVFREQ_GOV_USERSPACE
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tristate "Userspace"
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help
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Sets the frequency at the user specified one.
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This governor returns the user configured frequency if there
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has been an input to /sys/devices/.../power/devfreq_set_freq.
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Otherwise, the governor does not change the frequnecy
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given at the initialization.
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comment "DEVFREQ Drivers"
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config ARM_EXYNOS4_BUS_DEVFREQ
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bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
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depends on (CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
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select DEVFREQ_GOV_SIMPLE_ONDEMAND
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select PM_OPP
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help
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This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
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and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
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It reads PPMU counters of memory controllers and adjusts
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the operating frequencies and voltages with OPP support.
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This does not yet operate with optimal voltages.
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config ARM_EXYNOS5_BUS_DEVFREQ
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tristate "ARM Exynos5250 Bus DEVFREQ Driver"
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depends on SOC_EXYNOS5250
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select DEVFREQ_GOV_SIMPLE_ONDEMAND
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select PM_OPP
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help
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This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
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It reads PPMU counters of memory controllers and adjusts the
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operating frequencies and voltages with OPP support.
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config ARM_TEGRA_DEVFREQ
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tristate "Tegra DEVFREQ Driver"
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depends on ARCH_TEGRA_124_SOC
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select DEVFREQ_GOV_SIMPLE_ONDEMAND
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select PM_OPP
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help
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This adds the DEVFREQ driver for the Tegra family of SoCs.
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It reads ACTMON counters of memory controllers and adjusts the
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operating frequencies and voltages with OPP support.
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source "drivers/devfreq/event/Kconfig"
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endif # PM_DEVFREQ
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