| # SPDX-License-Identifier: GPL-2.0-only |
| menu "CPU Frequency scaling" |
| |
| config CPU_FREQ |
| bool "CPU Frequency scaling" |
| select SRCU |
| help |
| CPU Frequency scaling allows you to change the clock speed of |
| CPUs on the fly. This is a nice method to save power, because |
| the lower the CPU clock speed, the less power the CPU consumes. |
| |
| Note that this driver doesn't automatically change the CPU |
| clock speed, you need to either enable a dynamic cpufreq governor |
| (see below) after boot, or use a userspace tool. |
| |
| For details, take a look at <file:Documentation/cpu-freq>. |
| |
| If in doubt, say N. |
| |
| if CPU_FREQ |
| |
| config CPU_FREQ_GOV_ATTR_SET |
| bool |
| |
| config CPU_FREQ_GOV_COMMON |
| select CPU_FREQ_GOV_ATTR_SET |
| select IRQ_WORK |
| bool |
| |
| config CPU_FREQ_STAT |
| bool "CPU frequency transition statistics" |
| help |
| Export CPU frequency statistics information through sysfs. |
| |
| If in doubt, say N. |
| |
| choice |
| prompt "Default CPUFreq governor" |
| default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ |
| default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE |
| default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if X86_INTEL_PSTATE && SMP |
| default CPU_FREQ_DEFAULT_GOV_PERFORMANCE |
| help |
| This option sets which CPUFreq governor shall be loaded at |
| startup. If in doubt, use the default setting. |
| |
| config CPU_FREQ_DEFAULT_GOV_PERFORMANCE |
| bool "performance" |
| select CPU_FREQ_GOV_PERFORMANCE |
| help |
| Use the CPUFreq governor 'performance' as default. This sets |
| the frequency statically to the highest frequency supported by |
| the CPU. |
| |
| config CPU_FREQ_DEFAULT_GOV_POWERSAVE |
| bool "powersave" |
| select CPU_FREQ_GOV_POWERSAVE |
| help |
| Use the CPUFreq governor 'powersave' as default. This sets |
| the frequency statically to the lowest frequency supported by |
| the CPU. |
| |
| config CPU_FREQ_DEFAULT_GOV_USERSPACE |
| bool "userspace" |
| select CPU_FREQ_GOV_USERSPACE |
| help |
| Use the CPUFreq governor 'userspace' as default. This allows |
| you to set the CPU frequency manually or when a userspace |
| program shall be able to set the CPU dynamically without having |
| to enable the userspace governor manually. |
| |
| config CPU_FREQ_DEFAULT_GOV_ONDEMAND |
| bool "ondemand" |
| select CPU_FREQ_GOV_ONDEMAND |
| select CPU_FREQ_GOV_PERFORMANCE |
| help |
| Use the CPUFreq governor 'ondemand' as default. This allows |
| you to get a full dynamic frequency capable system by simply |
| loading your cpufreq low-level hardware driver. |
| Be aware that not all cpufreq drivers support the ondemand |
| governor. If unsure have a look at the help section of the |
| driver. Fallback governor will be the performance governor. |
| |
| config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
| bool "conservative" |
| select CPU_FREQ_GOV_CONSERVATIVE |
| select CPU_FREQ_GOV_PERFORMANCE |
| help |
| Use the CPUFreq governor 'conservative' as default. This allows |
| you to get a full dynamic frequency capable system by simply |
| loading your cpufreq low-level hardware driver. |
| Be aware that not all cpufreq drivers support the conservative |
| governor. If unsure have a look at the help section of the |
| driver. Fallback governor will be the performance governor. |
| |
| config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL |
| bool "schedutil" |
| depends on SMP |
| select CPU_FREQ_GOV_SCHEDUTIL |
| select CPU_FREQ_GOV_PERFORMANCE |
| help |
| Use the 'schedutil' CPUFreq governor by default. If unsure, |
| have a look at the help section of that governor. The fallback |
| governor will be 'performance'. |
| |
| endchoice |
| |
| config CPU_FREQ_GOV_PERFORMANCE |
| tristate "'performance' governor" |
| help |
| This cpufreq governor sets the frequency statically to the |
| highest available CPU frequency. |
| |
| To compile this driver as a module, choose M here: the |
| module will be called cpufreq_performance. |
| |
| If in doubt, say Y. |
| |
| config CPU_FREQ_GOV_POWERSAVE |
| tristate "'powersave' governor" |
| help |
| This cpufreq governor sets the frequency statically to the |
| lowest available CPU frequency. |
| |
| To compile this driver as a module, choose M here: the |
| module will be called cpufreq_powersave. |
| |
| If in doubt, say Y. |
| |
| config CPU_FREQ_GOV_USERSPACE |
| tristate "'userspace' governor for userspace frequency scaling" |
| help |
| Enable this cpufreq governor when you either want to set the |
| CPU frequency manually or when a userspace program shall |
| be able to set the CPU dynamically, like on LART |
| <http://www.lartmaker.nl/>. |
| |
| To compile this driver as a module, choose M here: the |
| module will be called cpufreq_userspace. |
| |
| For details, take a look at <file:Documentation/cpu-freq/>. |
| |
| If in doubt, say Y. |
| |
| config CPU_FREQ_GOV_ONDEMAND |
| tristate "'ondemand' cpufreq policy governor" |
| select CPU_FREQ_GOV_COMMON |
| help |
| 'ondemand' - This driver adds a dynamic cpufreq policy governor. |
| The governor does a periodic polling and |
| changes frequency based on the CPU utilization. |
| The support for this governor depends on CPU capability to |
| do fast frequency switching (i.e, very low latency frequency |
| transitions). |
| |
| To compile this driver as a module, choose M here: the |
| module will be called cpufreq_ondemand. |
| |
| For details, take a look at linux/Documentation/cpu-freq. |
| |
| If in doubt, say N. |
| |
| config CPU_FREQ_GOV_CONSERVATIVE |
| tristate "'conservative' cpufreq governor" |
| depends on CPU_FREQ |
| select CPU_FREQ_GOV_COMMON |
| help |
| 'conservative' - this driver is rather similar to the 'ondemand' |
| governor both in its source code and its purpose, the difference is |
| its optimisation for better suitability in a battery powered |
| environment. The frequency is gracefully increased and decreased |
| rather than jumping to 100% when speed is required. |
| |
| If you have a desktop machine then you should really be considering |
| the 'ondemand' governor instead, however if you are using a laptop, |
| PDA or even an AMD64 based computer (due to the unacceptable |
| step-by-step latency issues between the minimum and maximum frequency |
| transitions in the CPU) you will probably want to use this governor. |
| |
| To compile this driver as a module, choose M here: the |
| module will be called cpufreq_conservative. |
| |
| For details, take a look at linux/Documentation/cpu-freq. |
| |
| If in doubt, say N. |
| |
| config CPU_FREQ_GOV_SCHEDUTIL |
| bool "'schedutil' cpufreq policy governor" |
| depends on CPU_FREQ && SMP |
| select CPU_FREQ_GOV_ATTR_SET |
| select IRQ_WORK |
| help |
| This governor makes decisions based on the utilization data provided |
| by the scheduler. It sets the CPU frequency to be proportional to |
| the utilization/capacity ratio coming from the scheduler. If the |
| utilization is frequency-invariant, the new frequency is also |
| proportional to the maximum available frequency. If that is not the |
| case, it is proportional to the current frequency of the CPU. The |
| frequency tipping point is at utilization/capacity equal to 80% in |
| both cases. |
| |
| If in doubt, say N. |
| |
| comment "CPU frequency scaling drivers" |
| |
| config CPUFREQ_DT |
| tristate "Generic DT based cpufreq driver" |
| depends on HAVE_CLK && OF |
| select CPUFREQ_DT_PLATDEV |
| select PM_OPP |
| help |
| This adds a generic DT based cpufreq driver for frequency management. |
| It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) |
| systems. |
| |
| If in doubt, say N. |
| |
| config CPUFREQ_DT_PLATDEV |
| bool |
| help |
| This adds a generic DT based cpufreq platdev driver for frequency |
| management. This creates a 'cpufreq-dt' platform device, on the |
| supported platforms. |
| |
| If in doubt, say N. |
| |
| if X86 |
| source "drivers/cpufreq/Kconfig.x86" |
| endif |
| |
| if ARM || ARM64 |
| source "drivers/cpufreq/Kconfig.arm" |
| endif |
| |
| if PPC32 || PPC64 |
| source "drivers/cpufreq/Kconfig.powerpc" |
| endif |
| |
| if IA64 |
| config IA64_ACPI_CPUFREQ |
| tristate "ACPI Processor P-States driver" |
| depends on ACPI_PROCESSOR |
| help |
| This driver adds a CPUFreq driver which utilizes the ACPI |
| Processor Performance States. |
| |
| For details, take a look at <file:Documentation/cpu-freq/>. |
| |
| If in doubt, say N. |
| endif |
| |
| if MIPS |
| config BMIPS_CPUFREQ |
| tristate "BMIPS CPUfreq Driver" |
| help |
| This option adds a CPUfreq driver for BMIPS processors with |
| support for configurable CPU frequency. |
| |
| For now, BMIPS5 chips are supported (such as the Broadcom 7425). |
| |
| If in doubt, say N. |
| |
| config LOONGSON2_CPUFREQ |
| tristate "Loongson2 CPUFreq Driver" |
| depends on LEMOTE_MACH2F |
| help |
| This option adds a CPUFreq driver for loongson processors which |
| support software configurable cpu frequency. |
| |
| Loongson2F and it's successors support this feature. |
| |
| For details, take a look at <file:Documentation/cpu-freq/>. |
| |
| If in doubt, say N. |
| |
| config LOONGSON1_CPUFREQ |
| tristate "Loongson1 CPUFreq Driver" |
| depends on LOONGSON1_LS1B |
| help |
| This option adds a CPUFreq driver for loongson1 processors which |
| support software configurable cpu frequency. |
| |
| For details, take a look at <file:Documentation/cpu-freq/>. |
| |
| If in doubt, say N. |
| endif |
| |
| if SPARC64 |
| config SPARC_US3_CPUFREQ |
| tristate "UltraSPARC-III CPU Frequency driver" |
| help |
| This adds the CPUFreq driver for UltraSPARC-III processors. |
| |
| For details, take a look at <file:Documentation/cpu-freq>. |
| |
| If in doubt, say N. |
| |
| config SPARC_US2E_CPUFREQ |
| tristate "UltraSPARC-IIe CPU Frequency driver" |
| help |
| This adds the CPUFreq driver for UltraSPARC-IIe processors. |
| |
| For details, take a look at <file:Documentation/cpu-freq>. |
| |
| If in doubt, say N. |
| endif |
| |
| if SUPERH |
| config SH_CPU_FREQ |
| tristate "SuperH CPU Frequency driver" |
| help |
| This adds the cpufreq driver for SuperH. Any CPU that supports |
| clock rate rounding through the clock framework can use this |
| driver. While it will make the kernel slightly larger, this is |
| harmless for CPUs that don't support rate rounding. The driver |
| will also generate a notice in the boot log before disabling |
| itself if the CPU in question is not capable of rate rounding. |
| |
| For details, take a look at <file:Documentation/cpu-freq>. |
| |
| If unsure, say N. |
| endif |
| |
| config QORIQ_CPUFREQ |
| tristate "CPU frequency scaling driver for Freescale QorIQ SoCs" |
| depends on OF && COMMON_CLK && (PPC_E500MC || ARM || ARM64) |
| select CLK_QORIQ |
| help |
| This adds the CPUFreq driver support for Freescale QorIQ SoCs |
| which are capable of changing the CPU's frequency dynamically. |
| |
| endif |
| endmenu |
