| menuconfig PM_DEVFREQ |
| bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" |
| select SRCU |
| select PM_OPP |
| 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 frequency |
| given at the initialization. |
| |
| config DEVFREQ_GOV_PASSIVE |
| tristate "Passive" |
| help |
| Sets the frequency based on the frequency of its parent devfreq |
| device. This governor does not change the frequency by itself |
| through sysfs entries. The passive governor recommends that |
| devfreq device uses the OPP table to get the frequency/voltage. |
| |
| comment "DEVFREQ Drivers" |
| |
| config ARM_EXYNOS_BUS_DEVFREQ |
| tristate "ARM EXYNOS Generic Memory Bus DEVFREQ Driver" |
| depends on ARCH_EXYNOS || COMPILE_TEST |
| select DEVFREQ_GOV_SIMPLE_ONDEMAND |
| select DEVFREQ_GOV_PASSIVE |
| select DEVFREQ_EVENT_EXYNOS_PPMU |
| select PM_DEVFREQ_EVENT |
| select PM_OPP |
| help |
| This adds the common DEVFREQ driver for Exynos Memory bus. Exynos |
| Memory bus has one more group of memory bus (e.g, MIF and INT block). |
| Each memory bus group could contain many memoby bus block. It reads |
| PPMU counters of memory controllers by using DEVFREQ-event device |
| and adjusts the operating frequencies and voltages with OPP support. |
| This does not yet operate with optimal voltages. |
| |
| config ARM_TEGRA_DEVFREQ |
| tristate "Tegra DEVFREQ Driver" |
| depends on ARCH_TEGRA_124_SOC |
| select DEVFREQ_GOV_SIMPLE_ONDEMAND |
| select PM_OPP |
| help |
| This adds the DEVFREQ driver for the Tegra family of SoCs. |
| It reads ACTMON counters of memory controllers and adjusts the |
| operating frequencies and voltages with OPP support. |
| |
| config ARM_RK3399_DMC_DEVFREQ |
| tristate "ARM RK3399 DMC DEVFREQ Driver" |
| depends on ARCH_ROCKCHIP |
| select DEVFREQ_EVENT_ROCKCHIP_DFI |
| select DEVFREQ_GOV_SIMPLE_ONDEMAND |
| select PM_DEVFREQ_EVENT |
| select PM_OPP |
| help |
| This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller). |
| It sets the frequency for the memory controller and reads the usage counts |
| from hardware. |
| |
| source "drivers/devfreq/event/Kconfig" |
| |
| endif # PM_DEVFREQ |