1menuconfig PM_DEVFREQ 2 bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" 3 select SRCU 4 select PM_OPP 5 help 6 A device may have a list of frequencies and voltages available. 7 devfreq, a generic DVFS framework can be registered for a device 8 in order to let the governor provided to devfreq choose an 9 operating frequency based on the device driver's policy. 10 11 Each device may have its own governor and policy. Devfreq can 12 reevaluate the device state periodically and/or based on the 13 notification to "nb", a notifier block, of devfreq. 14 15 Like some CPUs with CPUfreq, a device may have multiple clocks. 16 However, because the clock frequencies of a single device are 17 determined by the single device's state, an instance of devfreq 18 is attached to a single device and returns a "representative" 19 clock frequency of the device, which is also attached 20 to a device by 1-to-1. The device registering devfreq takes the 21 responsibility to "interpret" the representative frequency and 22 to set its every clock accordingly with the "target" callback 23 given to devfreq. 24 25 When OPP is used with the devfreq device, it is recommended to 26 register devfreq's nb to the OPP's notifier head. If OPP is 27 used with the devfreq device, you may use OPP helper 28 functions defined in devfreq.h. 29 30if PM_DEVFREQ 31 32comment "DEVFREQ Governors" 33 34config DEVFREQ_GOV_SIMPLE_ONDEMAND 35 tristate "Simple Ondemand" 36 help 37 Chooses frequency based on the recent load on the device. Works 38 similar as ONDEMAND governor of CPUFREQ does. A device with 39 Simple-Ondemand should be able to provide busy/total counter 40 values that imply the usage rate. A device may provide tuned 41 values to the governor with data field at devfreq_add_device(). 42 43config DEVFREQ_GOV_PERFORMANCE 44 tristate "Performance" 45 help 46 Sets the frequency at the maximum available frequency. 47 This governor always returns UINT_MAX as frequency so that 48 the DEVFREQ framework returns the highest frequency available 49 at any time. 50 51config DEVFREQ_GOV_POWERSAVE 52 tristate "Powersave" 53 help 54 Sets the frequency at the minimum available frequency. 55 This governor always returns 0 as frequency so that 56 the DEVFREQ framework returns the lowest frequency available 57 at any time. 58 59config DEVFREQ_GOV_USERSPACE 60 tristate "Userspace" 61 help 62 Sets the frequency at the user specified one. 63 This governor returns the user configured frequency if there 64 has been an input to /sys/devices/.../power/devfreq_set_freq. 65 Otherwise, the governor does not change the frequency 66 given at the initialization. 67 68config DEVFREQ_GOV_PASSIVE 69 tristate "Passive" 70 help 71 Sets the frequency based on the frequency of its parent devfreq 72 device. This governor does not change the frequency by itself 73 through sysfs entries. The passive governor recommends that 74 devfreq device uses the OPP table to get the frequency/voltage. 75 76comment "DEVFREQ Drivers" 77 78config ARM_EXYNOS_BUS_DEVFREQ 79 tristate "ARM EXYNOS Generic Memory Bus DEVFREQ Driver" 80 depends on ARCH_EXYNOS || COMPILE_TEST 81 select DEVFREQ_GOV_SIMPLE_ONDEMAND 82 select DEVFREQ_GOV_PASSIVE 83 select DEVFREQ_EVENT_EXYNOS_PPMU 84 select PM_DEVFREQ_EVENT 85 select PM_OPP 86 help 87 This adds the common DEVFREQ driver for Exynos Memory bus. Exynos 88 Memory bus has one more group of memory bus (e.g, MIF and INT block). 89 Each memory bus group could contain many memoby bus block. It reads 90 PPMU counters of memory controllers by using DEVFREQ-event device 91 and adjusts the operating frequencies and voltages with OPP support. 92 This does not yet operate with optimal voltages. 93 94config ARM_TEGRA_DEVFREQ 95 tristate "Tegra DEVFREQ Driver" 96 depends on ARCH_TEGRA_124_SOC 97 select DEVFREQ_GOV_SIMPLE_ONDEMAND 98 select PM_OPP 99 help 100 This adds the DEVFREQ driver for the Tegra family of SoCs. 101 It reads ACTMON counters of memory controllers and adjusts the 102 operating frequencies and voltages with OPP support. 103 104config ARM_RK3399_DMC_DEVFREQ 105 tristate "ARM RK3399 DMC DEVFREQ Driver" 106 depends on ARCH_ROCKCHIP 107 select DEVFREQ_EVENT_ROCKCHIP_DFI 108 select DEVFREQ_GOV_SIMPLE_ONDEMAND 109 select PM_DEVFREQ_EVENT 110 select PM_OPP 111 help 112 This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller). 113 It sets the frequency for the memory controller and reads the usage counts 114 from hardware. 115 116source "drivers/devfreq/event/Kconfig" 117 118endif # PM_DEVFREQ 119