1 # SPDX-License-Identifier: GPL-2.0-only 2 menuconfig PM_DEVFREQ 3 bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" 4 select SRCU 5 select PM_OPP 6 help 7 A device may have a list of frequencies and voltages available. 8 devfreq, a generic DVFS framework can be registered for a device 9 in order to let the governor provided to devfreq choose an 10 operating frequency based on the device driver's policy. 11 12 Each device may have its own governor and policy. Devfreq can 13 reevaluate the device state periodically and/or based on the 14 notification to "nb", a notifier block, of devfreq. 15 16 Like some CPUs with CPUfreq, a device may have multiple clocks. 17 However, because the clock frequencies of a single device are 18 determined by the single device's state, an instance of devfreq 19 is attached to a single device and returns a "representative" 20 clock frequency of the device, which is also attached 21 to a device by 1-to-1. The device registering devfreq takes the 22 responsibility to "interpret" the representative frequency and 23 to set its every clock accordingly with the "target" callback 24 given to devfreq. 25 26 When OPP is used with the devfreq device, it is recommended to 27 register devfreq's nb to the OPP's notifier head. If OPP is 28 used with the devfreq device, you may use OPP helper 29 functions defined in devfreq.h. 30 31 if PM_DEVFREQ 32 33 comment "DEVFREQ Governors" 34 35 config DEVFREQ_GOV_SIMPLE_ONDEMAND 36 tristate "Simple Ondemand" 37 help 38 Chooses frequency based on the recent load on the device. Works 39 similar as ONDEMAND governor of CPUFREQ does. A device with 40 Simple-Ondemand should be able to provide busy/total counter 41 values that imply the usage rate. A device may provide tuned 42 values to the governor with data field at devfreq_add_device(). 43 44 config DEVFREQ_GOV_PERFORMANCE 45 tristate "Performance" 46 help 47 Sets the frequency at the maximum available frequency. 48 This governor always returns UINT_MAX as frequency so that 49 the DEVFREQ framework returns the highest frequency available 50 at any time. 51 52 config DEVFREQ_GOV_POWERSAVE 53 tristate "Powersave" 54 help 55 Sets the frequency at the minimum available frequency. 56 This governor always returns 0 as frequency so that 57 the DEVFREQ framework returns the lowest frequency available 58 at any time. 59 60 config DEVFREQ_GOV_USERSPACE 61 tristate "Userspace" 62 help 63 Sets the frequency at the user specified one. 64 This governor returns the user configured frequency if there 65 has been an input to /sys/devices/.../power/devfreq_set_freq. 66 Otherwise, the governor does not change the frequency 67 given at the initialization. 68 69 config DEVFREQ_GOV_PASSIVE 70 tristate "Passive" 71 help 72 Sets the frequency based on the frequency of its parent devfreq 73 device. This governor does not change the frequency by itself 74 through sysfs entries. The passive governor recommends that 75 devfreq device uses the OPP table to get the frequency/voltage. 76 77 comment "DEVFREQ Drivers" 78 79 config ARM_EXYNOS_BUS_DEVFREQ 80 tristate "ARM Exynos Generic Memory Bus DEVFREQ Driver" 81 depends on ARCH_EXYNOS || COMPILE_TEST 82 select DEVFREQ_GOV_SIMPLE_ONDEMAND 83 select DEVFREQ_GOV_PASSIVE 84 select DEVFREQ_EVENT_EXYNOS_PPMU 85 select PM_DEVFREQ_EVENT 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 94 config ARM_IMX_BUS_DEVFREQ 95 tristate "i.MX Generic Bus DEVFREQ Driver" 96 depends on ARCH_MXC || COMPILE_TEST 97 select DEVFREQ_GOV_USERSPACE 98 help 99 This adds the generic DEVFREQ driver for i.MX interconnects. It 100 allows adjusting NIC/NOC frequency. 101 102 config ARM_IMX8M_DDRC_DEVFREQ 103 tristate "i.MX8M DDRC DEVFREQ Driver" 104 depends on (ARCH_MXC && HAVE_ARM_SMCCC) || \ 105 (COMPILE_TEST && HAVE_ARM_SMCCC) 106 select DEVFREQ_GOV_SIMPLE_ONDEMAND 107 select DEVFREQ_GOV_USERSPACE 108 help 109 This adds the DEVFREQ driver for the i.MX8M DDR Controller. It allows 110 adjusting DRAM frequency. 111 112 config ARM_TEGRA_DEVFREQ 113 tristate "NVIDIA Tegra30/114/124/210 DEVFREQ Driver" 114 depends on ARCH_TEGRA_3x_SOC || ARCH_TEGRA_114_SOC || \ 115 ARCH_TEGRA_132_SOC || ARCH_TEGRA_124_SOC || \ 116 ARCH_TEGRA_210_SOC || \ 117 COMPILE_TEST 118 depends on COMMON_CLK 119 help 120 This adds the DEVFREQ driver for the Tegra family of SoCs. 121 It reads ACTMON counters of memory controllers and adjusts the 122 operating frequencies and voltages with OPP support. 123 124 config ARM_TEGRA20_DEVFREQ 125 tristate "NVIDIA Tegra20 DEVFREQ Driver" 126 depends on (TEGRA_MC && TEGRA20_EMC) || COMPILE_TEST 127 depends on COMMON_CLK 128 select DEVFREQ_GOV_SIMPLE_ONDEMAND 129 help 130 This adds the DEVFREQ driver for the Tegra20 family of SoCs. 131 It reads Memory Controller counters and adjusts the operating 132 frequencies and voltages with OPP support. 133 134 config ARM_RK3399_DMC_DEVFREQ 135 tristate "ARM RK3399 DMC DEVFREQ Driver" 136 depends on (ARCH_ROCKCHIP && HAVE_ARM_SMCCC) || \ 137 (COMPILE_TEST && HAVE_ARM_SMCCC) 138 select DEVFREQ_EVENT_ROCKCHIP_DFI 139 select DEVFREQ_GOV_SIMPLE_ONDEMAND 140 select PM_DEVFREQ_EVENT 141 help 142 This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller). 143 It sets the frequency for the memory controller and reads the usage counts 144 from hardware. 145 146 source "drivers/devfreq/event/Kconfig" 147 148 endif # PM_DEVFREQ 149