| 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 CPU_FREQ_SA1100 || CPU_FREQ_SA1110 |
| 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 "PowerPC CPU frequency scaling drivers" |
| depends on PPC32 || PPC64 |
| source "drivers/cpufreq/Kconfig.powerpc" |
| endmenu |
| |
| endif |
| endmenu |
