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Diffstat (limited to 'drivers/cpufreq/Kconfig')
| -rw-r--r-- | drivers/cpufreq/Kconfig | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig new file mode 100644 index 0000000..5f076ae --- /dev/null +++ b/drivers/cpufreq/Kconfig @@ -0,0 +1,193 @@ +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_DEBUG + bool "Enable CPUfreq debugging" + help + Say Y here to enable CPUfreq subsystem (including drivers) + debugging. You will need to activate it via the kernel + command line by passing + cpufreq.debug=<value> + + To get <value>, add + 1 to activate CPUfreq core debugging, + 2 to activate CPUfreq drivers debugging, and + 4 to activate CPUfreq governor debugging + +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 EMBEDDED + 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 an 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 an 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 + 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 + 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. + +endif # CPU_FREQ |
