| menu "CPU Frequency scaling" | |
| config CPU_FREQ | |
| bool "CPU Frequency scaling" | |
| 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_TABLE | |
| tristate | |
| config CPU_FREQ_GOV_COMMON | |
| bool | |
| config CPU_FREQ_STAT | |
| tristate "CPU frequency translation statistics" | |
| select CPU_FREQ_TABLE | |
| default y | |
| help | |
| This driver exports CPU frequency statistics information through sysfs | |
| file system. | |
| To compile this driver as a module, choose M here: the | |
| module will be called cpufreq_stats. | |
| If in doubt, say N. | |
| config CPU_FREQ_STAT_DETAILS | |
| bool "CPU frequency translation statistics details" | |
| depends on CPU_FREQ_STAT | |
| help | |
| This will show detail CPU frequency translation table in sysfs file | |
| system. | |
| 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_PERFORMANCE | |
| help | |
| This option sets which CPUFreq governor shall be loaded at | |
| startup. If in doubt, select 'performance'. | |
| 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" | |
| depends on EXPERT | |
| 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. | |
| 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_TABLE | |
| 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 GENERIC_CPUFREQ_CPU0 | |
| tristate "Generic CPU0 cpufreq driver" | |
| depends on HAVE_CLK && REGULATOR && PM_OPP && OF | |
| select CPU_FREQ_TABLE | |
| help | |
| This adds a generic cpufreq driver for CPU0 frequency management. | |
| It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) | |
| systems which share clock and voltage across all CPUs. | |
| If in doubt, say N. | |
| menu "x86 CPU frequency scaling drivers" | |
| depends on X86 | |
| source "drivers/cpufreq/Kconfig.x86" | |
| endmenu | |
| menu "ARM CPU frequency scaling drivers" | |
| depends on ARM | |
| source "drivers/cpufreq/Kconfig.arm" | |
| endmenu | |
| menu "AVR32 CPU frequency scaling drivers" | |
| depends on AVR32 | |
| config AVR32_AT32AP_CPUFREQ | |
| bool "CPU frequency driver for AT32AP" | |
| depends on PLATFORM_AT32AP | |
| default n | |
| help | |
| This enables the CPU frequency driver for AT32AP processors. | |
| If in doubt, say N. | |
| endmenu | |
| menu "CPUFreq processor drivers" | |
| depends on IA64 | |
| config IA64_ACPI_CPUFREQ | |
| tristate "ACPI Processor P-States driver" | |
| select CPU_FREQ_TABLE | |
| 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. | |
| endmenu | |
| menu "MIPS CPUFreq processor drivers" | |
| depends on MIPS | |
| config LOONGSON2_CPUFREQ | |
| tristate "Loongson2 CPUFreq Driver" | |
| select CPU_FREQ_TABLE | |
| 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. | |
| endmenu | |
| menu "PowerPC CPU frequency scaling drivers" | |
| depends on PPC32 || PPC64 | |
| source "drivers/cpufreq/Kconfig.powerpc" | |
| endmenu | |
| menu "SPARC CPU frequency scaling drivers" | |
| depends on SPARC64 | |
| config SPARC_US3_CPUFREQ | |
| tristate "UltraSPARC-III CPU Frequency driver" | |
| select CPU_FREQ_TABLE | |
| 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" | |
| select CPU_FREQ_TABLE | |
| 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. | |
| endmenu | |
| menu "SH CPU Frequency scaling" | |
| depends on SUPERH | |
| config SH_CPU_FREQ | |
| tristate "SuperH CPU Frequency driver" | |
| select CPU_FREQ_TABLE | |
| 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. | |
| endmenu | |
| endif | |
| endmenu |