1bb0a56ecSDave Jonesmenu "CPU Frequency scaling" 2bb0a56ecSDave Jones 31da177e4SLinus Torvaldsconfig CPU_FREQ 41da177e4SLinus Torvalds bool "CPU Frequency scaling" 51da177e4SLinus Torvalds help 61da177e4SLinus Torvalds CPU Frequency scaling allows you to change the clock speed of 71da177e4SLinus Torvalds CPUs on the fly. This is a nice method to save power, because 81da177e4SLinus Torvalds the lower the CPU clock speed, the less power the CPU consumes. 91da177e4SLinus Torvalds 101da177e4SLinus Torvalds Note that this driver doesn't automatically change the CPU 111da177e4SLinus Torvalds clock speed, you need to either enable a dynamic cpufreq governor 121da177e4SLinus Torvalds (see below) after boot, or use a userspace tool. 131da177e4SLinus Torvalds 141da177e4SLinus Torvalds For details, take a look at <file:Documentation/cpu-freq>. 151da177e4SLinus Torvalds 161da177e4SLinus Torvalds If in doubt, say N. 171da177e4SLinus Torvalds 181da177e4SLinus Torvaldsif CPU_FREQ 191da177e4SLinus Torvalds 201e15f295SLarry Fingerconfig CPU_FREQ_GOV_COMMON 211e15f295SLarry Finger bool 221e15f295SLarry Finger 232fb4719bSLukasz Majewskiconfig CPU_FREQ_BOOST_SW 242fb4719bSLukasz Majewski bool 252fb4719bSLukasz Majewski depends on THERMAL 262fb4719bSLukasz Majewski 271da177e4SLinus Torvaldsconfig CPU_FREQ_STAT 281da177e4SLinus Torvalds tristate "CPU frequency translation statistics" 291da177e4SLinus Torvalds default y 301da177e4SLinus Torvalds help 311da177e4SLinus Torvalds This driver exports CPU frequency statistics information through sysfs 329101be53SMike Frysinger file system. 339101be53SMike Frysinger 349101be53SMike Frysinger To compile this driver as a module, choose M here: the 359101be53SMike Frysinger module will be called cpufreq_stats. 369101be53SMike Frysinger 379101be53SMike Frysinger If in doubt, say N. 381da177e4SLinus Torvalds 391da177e4SLinus Torvaldsconfig CPU_FREQ_STAT_DETAILS 401da177e4SLinus Torvalds bool "CPU frequency translation statistics details" 411da177e4SLinus Torvalds depends on CPU_FREQ_STAT 421da177e4SLinus Torvalds help 431da177e4SLinus Torvalds This will show detail CPU frequency translation table in sysfs file 449101be53SMike Frysinger system. 459101be53SMike Frysinger 469101be53SMike Frysinger If in doubt, say N. 471da177e4SLinus Torvalds 481da177e4SLinus Torvaldschoice 491da177e4SLinus Torvalds prompt "Default CPUFreq governor" 50559f56c7SAlexander Shiyan default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ 511da177e4SLinus Torvalds default CPU_FREQ_DEFAULT_GOV_PERFORMANCE 521da177e4SLinus Torvalds help 531da177e4SLinus Torvalds This option sets which CPUFreq governor shall be loaded at 541da177e4SLinus Torvalds startup. If in doubt, select 'performance'. 551da177e4SLinus Torvalds 561da177e4SLinus Torvaldsconfig CPU_FREQ_DEFAULT_GOV_PERFORMANCE 571da177e4SLinus Torvalds bool "performance" 581da177e4SLinus Torvalds select CPU_FREQ_GOV_PERFORMANCE 591da177e4SLinus Torvalds help 601da177e4SLinus Torvalds Use the CPUFreq governor 'performance' as default. This sets 611da177e4SLinus Torvalds the frequency statically to the highest frequency supported by 621da177e4SLinus Torvalds the CPU. 631da177e4SLinus Torvalds 6430d221dbSAlessandro Guidoconfig CPU_FREQ_DEFAULT_GOV_POWERSAVE 6530d221dbSAlessandro Guido bool "powersave" 666a108a14SDavid Rientjes depends on EXPERT 6730d221dbSAlessandro Guido select CPU_FREQ_GOV_POWERSAVE 6830d221dbSAlessandro Guido help 6930d221dbSAlessandro Guido Use the CPUFreq governor 'powersave' as default. This sets 7030d221dbSAlessandro Guido the frequency statically to the lowest frequency supported by 7130d221dbSAlessandro Guido the CPU. 7230d221dbSAlessandro Guido 731da177e4SLinus Torvaldsconfig CPU_FREQ_DEFAULT_GOV_USERSPACE 741da177e4SLinus Torvalds bool "userspace" 751da177e4SLinus Torvalds select CPU_FREQ_GOV_USERSPACE 761da177e4SLinus Torvalds help 771da177e4SLinus Torvalds Use the CPUFreq governor 'userspace' as default. This allows 780211a9c8SFrederik Schwarzer you to set the CPU frequency manually or when a userspace 791da177e4SLinus Torvalds program shall be able to set the CPU dynamically without having 801da177e4SLinus Torvalds to enable the userspace governor manually. 811da177e4SLinus Torvalds 821c256245SThomas Renningerconfig CPU_FREQ_DEFAULT_GOV_ONDEMAND 831c256245SThomas Renninger bool "ondemand" 841c256245SThomas Renninger select CPU_FREQ_GOV_ONDEMAND 851c256245SThomas Renninger select CPU_FREQ_GOV_PERFORMANCE 861c256245SThomas Renninger help 871c256245SThomas Renninger Use the CPUFreq governor 'ondemand' as default. This allows 881c256245SThomas Renninger you to get a full dynamic frequency capable system by simply 891c256245SThomas Renninger loading your cpufreq low-level hardware driver. 901c256245SThomas Renninger Be aware that not all cpufreq drivers support the ondemand 911c256245SThomas Renninger governor. If unsure have a look at the help section of the 921c256245SThomas Renninger driver. Fallback governor will be the performance governor. 931c256245SThomas Renninger 941c256245SThomas Renningerconfig CPU_FREQ_DEFAULT_GOV_CONSERVATIVE 951c256245SThomas Renninger bool "conservative" 961c256245SThomas Renninger select CPU_FREQ_GOV_CONSERVATIVE 971c256245SThomas Renninger select CPU_FREQ_GOV_PERFORMANCE 981c256245SThomas Renninger help 991c256245SThomas Renninger Use the CPUFreq governor 'conservative' as default. This allows 1001c256245SThomas Renninger you to get a full dynamic frequency capable system by simply 1011c256245SThomas Renninger loading your cpufreq low-level hardware driver. 1021c256245SThomas Renninger Be aware that not all cpufreq drivers support the conservative 1031c256245SThomas Renninger governor. If unsure have a look at the help section of the 1041c256245SThomas Renninger driver. Fallback governor will be the performance governor. 1051da177e4SLinus Torvaldsendchoice 1061da177e4SLinus Torvalds 1071da177e4SLinus Torvaldsconfig CPU_FREQ_GOV_PERFORMANCE 1081da177e4SLinus Torvalds tristate "'performance' governor" 1091da177e4SLinus Torvalds help 1101da177e4SLinus Torvalds This cpufreq governor sets the frequency statically to the 1111da177e4SLinus Torvalds highest available CPU frequency. 1121da177e4SLinus Torvalds 1139101be53SMike Frysinger To compile this driver as a module, choose M here: the 1149101be53SMike Frysinger module will be called cpufreq_performance. 1159101be53SMike Frysinger 1161da177e4SLinus Torvalds If in doubt, say Y. 1171da177e4SLinus Torvalds 1181da177e4SLinus Torvaldsconfig CPU_FREQ_GOV_POWERSAVE 1191da177e4SLinus Torvalds tristate "'powersave' governor" 1201da177e4SLinus Torvalds help 1211da177e4SLinus Torvalds This cpufreq governor sets the frequency statically to the 1221da177e4SLinus Torvalds lowest available CPU frequency. 1231da177e4SLinus Torvalds 1249101be53SMike Frysinger To compile this driver as a module, choose M here: the 1259101be53SMike Frysinger module will be called cpufreq_powersave. 1269101be53SMike Frysinger 1271da177e4SLinus Torvalds If in doubt, say Y. 1281da177e4SLinus Torvalds 1291da177e4SLinus Torvaldsconfig CPU_FREQ_GOV_USERSPACE 1301da177e4SLinus Torvalds tristate "'userspace' governor for userspace frequency scaling" 1311da177e4SLinus Torvalds help 1321da177e4SLinus Torvalds Enable this cpufreq governor when you either want to set the 1330211a9c8SFrederik Schwarzer CPU frequency manually or when a userspace program shall 1341da177e4SLinus Torvalds be able to set the CPU dynamically, like on LART 1354c41251eSErik Mouw <http://www.lartmaker.nl/>. 1361da177e4SLinus Torvalds 1379101be53SMike Frysinger To compile this driver as a module, choose M here: the 1389101be53SMike Frysinger module will be called cpufreq_userspace. 1399101be53SMike Frysinger 1401da177e4SLinus Torvalds For details, take a look at <file:Documentation/cpu-freq/>. 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds If in doubt, say Y. 1431da177e4SLinus Torvalds 1441da177e4SLinus Torvaldsconfig CPU_FREQ_GOV_ONDEMAND 1451da177e4SLinus Torvalds tristate "'ondemand' cpufreq policy governor" 1461e15f295SLarry Finger select CPU_FREQ_GOV_COMMON 1471da177e4SLinus Torvalds help 1481da177e4SLinus Torvalds 'ondemand' - This driver adds a dynamic cpufreq policy governor. 1491da177e4SLinus Torvalds The governor does a periodic polling and 1501da177e4SLinus Torvalds changes frequency based on the CPU utilization. 1511da177e4SLinus Torvalds The support for this governor depends on CPU capability to 1521da177e4SLinus Torvalds do fast frequency switching (i.e, very low latency frequency 1531da177e4SLinus Torvalds transitions). 1541da177e4SLinus Torvalds 1559101be53SMike Frysinger To compile this driver as a module, choose M here: the 1569101be53SMike Frysinger module will be called cpufreq_ondemand. 1579101be53SMike Frysinger 1581da177e4SLinus Torvalds For details, take a look at linux/Documentation/cpu-freq. 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds If in doubt, say N. 1611da177e4SLinus Torvalds 162b9170836SDave Jonesconfig CPU_FREQ_GOV_CONSERVATIVE 163b9170836SDave Jones tristate "'conservative' cpufreq governor" 164b9170836SDave Jones depends on CPU_FREQ 1651e15f295SLarry Finger select CPU_FREQ_GOV_COMMON 166b9170836SDave Jones help 167b9170836SDave Jones 'conservative' - this driver is rather similar to the 'ondemand' 168b9170836SDave Jones governor both in its source code and its purpose, the difference is 169b9170836SDave Jones its optimisation for better suitability in a battery powered 170b9170836SDave Jones environment. The frequency is gracefully increased and decreased 171b9170836SDave Jones rather than jumping to 100% when speed is required. 172b9170836SDave Jones 173b9170836SDave Jones If you have a desktop machine then you should really be considering 174b9170836SDave Jones the 'ondemand' governor instead, however if you are using a laptop, 175b9170836SDave Jones PDA or even an AMD64 based computer (due to the unacceptable 176b9170836SDave Jones step-by-step latency issues between the minimum and maximum frequency 177b9170836SDave Jones transitions in the CPU) you will probably want to use this governor. 178b9170836SDave Jones 1799101be53SMike Frysinger To compile this driver as a module, choose M here: the 1809101be53SMike Frysinger module will be called cpufreq_conservative. 1819101be53SMike Frysinger 182b9170836SDave Jones For details, take a look at linux/Documentation/cpu-freq. 183b9170836SDave Jones 184b9170836SDave Jones If in doubt, say N. 185b9170836SDave Jones 18695ceafd4SShawn Guoconfig GENERIC_CPUFREQ_CPU0 1875553f9e2SShawn Guo tristate "Generic CPU0 cpufreq driver" 188*5fbfbcd3SViresh Kumar depends on HAVE_CLK && OF 189109df086SMark Brown select PM_OPP 19095ceafd4SShawn Guo help 19195ceafd4SShawn Guo This adds a generic cpufreq driver for CPU0 frequency management. 19295ceafd4SShawn Guo It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) 19395ceafd4SShawn Guo systems which share clock and voltage across all CPUs. 19495ceafd4SShawn Guo 19595ceafd4SShawn Guo If in doubt, say N. 19695ceafd4SShawn Guo 197bb0a56ecSDave Jonesmenu "x86 CPU frequency scaling drivers" 198bb0a56ecSDave Jonesdepends on X86 199bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig.x86" 200bb0a56ecSDave Jonesendmenu 201bb0a56ecSDave Jones 202f7d77079SKukjin Kimmenu "ARM CPU frequency scaling drivers" 203addea9efSRob Herringdepends on ARM || ARM64 204f7d77079SKukjin Kimsource "drivers/cpufreq/Kconfig.arm" 205f7d77079SKukjin Kimendmenu 206f7d77079SKukjin Kim 20781c720c9SViresh Kumarmenu "AVR32 CPU frequency scaling drivers" 20881c720c9SViresh Kumardepends on AVR32 20981c720c9SViresh Kumar 21081c720c9SViresh Kumarconfig AVR32_AT32AP_CPUFREQ 21181c720c9SViresh Kumar bool "CPU frequency driver for AT32AP" 21281c720c9SViresh Kumar depends on PLATFORM_AT32AP 21381c720c9SViresh Kumar default n 21481c720c9SViresh Kumar help 21581c720c9SViresh Kumar This enables the CPU frequency driver for AT32AP processors. 21681c720c9SViresh Kumar If in doubt, say N. 21781c720c9SViresh Kumar 21881c720c9SViresh Kumarendmenu 21981c720c9SViresh Kumar 220ab423e43SViresh Kumarmenu "CPUFreq processor drivers" 221ab423e43SViresh Kumardepends on IA64 222ab423e43SViresh Kumar 223ab423e43SViresh Kumarconfig IA64_ACPI_CPUFREQ 224ab423e43SViresh Kumar tristate "ACPI Processor P-States driver" 225ab423e43SViresh Kumar depends on ACPI_PROCESSOR 226ab423e43SViresh Kumar help 227ab423e43SViresh Kumar This driver adds a CPUFreq driver which utilizes the ACPI 228ab423e43SViresh Kumar Processor Performance States. 229ab423e43SViresh Kumar 230ab423e43SViresh Kumar For details, take a look at <file:Documentation/cpu-freq/>. 231ab423e43SViresh Kumar 232ab423e43SViresh Kumar If in doubt, say N. 233ab423e43SViresh Kumar 234ab423e43SViresh Kumarendmenu 235ab423e43SViresh Kumar 2367a998935SViresh Kumarmenu "MIPS CPUFreq processor drivers" 2377a998935SViresh Kumardepends on MIPS 2387a998935SViresh Kumar 2397a998935SViresh Kumarconfig LOONGSON2_CPUFREQ 2407a998935SViresh Kumar tristate "Loongson2 CPUFreq Driver" 2417a998935SViresh Kumar help 2427a998935SViresh Kumar This option adds a CPUFreq driver for loongson processors which 2437a998935SViresh Kumar support software configurable cpu frequency. 2447a998935SViresh Kumar 2457a998935SViresh Kumar Loongson2F and it's successors support this feature. 2467a998935SViresh Kumar 2477a998935SViresh Kumar For details, take a look at <file:Documentation/cpu-freq/>. 2487a998935SViresh Kumar 2497a998935SViresh Kumar If in doubt, say N. 2507a998935SViresh Kumar 2517a998935SViresh Kumarendmenu 2527a998935SViresh Kumar 2535d8c6658SDmitry Eremin-Solenikovmenu "PowerPC CPU frequency scaling drivers" 2545d8c6658SDmitry Eremin-Solenikovdepends on PPC32 || PPC64 2555d8c6658SDmitry Eremin-Solenikovsource "drivers/cpufreq/Kconfig.powerpc" 2565d8c6658SDmitry Eremin-Solenikovendmenu 2575d8c6658SDmitry Eremin-Solenikov 258764295aeSViresh Kumarmenu "SPARC CPU frequency scaling drivers" 259764295aeSViresh Kumardepends on SPARC64 260764295aeSViresh Kumarconfig SPARC_US3_CPUFREQ 261764295aeSViresh Kumar tristate "UltraSPARC-III CPU Frequency driver" 262764295aeSViresh Kumar help 263764295aeSViresh Kumar This adds the CPUFreq driver for UltraSPARC-III processors. 264764295aeSViresh Kumar 265764295aeSViresh Kumar For details, take a look at <file:Documentation/cpu-freq>. 266764295aeSViresh Kumar 267764295aeSViresh Kumar If in doubt, say N. 268764295aeSViresh Kumar 269764295aeSViresh Kumarconfig SPARC_US2E_CPUFREQ 270764295aeSViresh Kumar tristate "UltraSPARC-IIe CPU Frequency driver" 271764295aeSViresh Kumar help 272764295aeSViresh Kumar This adds the CPUFreq driver for UltraSPARC-IIe processors. 273764295aeSViresh Kumar 274764295aeSViresh Kumar For details, take a look at <file:Documentation/cpu-freq>. 275764295aeSViresh Kumar 276764295aeSViresh Kumar If in doubt, say N. 277764295aeSViresh Kumarendmenu 278764295aeSViresh Kumar 2797258267eSViresh Kumarmenu "SH CPU Frequency scaling" 2807258267eSViresh Kumardepends on SUPERH 2817258267eSViresh Kumarconfig SH_CPU_FREQ 2827258267eSViresh Kumar tristate "SuperH CPU Frequency driver" 2837258267eSViresh Kumar help 2847258267eSViresh Kumar This adds the cpufreq driver for SuperH. Any CPU that supports 2857258267eSViresh Kumar clock rate rounding through the clock framework can use this 2867258267eSViresh Kumar driver. While it will make the kernel slightly larger, this is 2877258267eSViresh Kumar harmless for CPUs that don't support rate rounding. The driver 2887258267eSViresh Kumar will also generate a notice in the boot log before disabling 2897258267eSViresh Kumar itself if the CPU in question is not capable of rate rounding. 2907258267eSViresh Kumar 2917258267eSViresh Kumar For details, take a look at <file:Documentation/cpu-freq>. 2927258267eSViresh Kumar 2937258267eSViresh Kumar If unsure, say N. 2947258267eSViresh Kumarendmenu 2957258267eSViresh Kumar 296bb0a56ecSDave Jonesendif 297bb0a56ecSDave Jonesendmenu 298