1menu "CPU Frequency scaling" 2 3config CPU_FREQ 4 bool "CPU Frequency scaling" 5 help 6 CPU Frequency scaling allows you to change the clock speed of 7 CPUs on the fly. This is a nice method to save power, because 8 the lower the CPU clock speed, the less power the CPU consumes. 9 10 Note that this driver doesn't automatically change the CPU 11 clock speed, you need to either enable a dynamic cpufreq governor 12 (see below) after boot, or use a userspace tool. 13 14 For details, take a look at <file:Documentation/cpu-freq>. 15 16 If in doubt, say N. 17 18if CPU_FREQ 19 20config CPU_FREQ_GOV_COMMON 21 bool 22 23config CPU_FREQ_BOOST_SW 24 bool 25 depends on THERMAL 26 27config CPU_FREQ_STAT 28 tristate "CPU frequency translation statistics" 29 default y 30 help 31 This driver exports CPU frequency statistics information through sysfs 32 file system. 33 34 To compile this driver as a module, choose M here: the 35 module will be called cpufreq_stats. 36 37 If in doubt, say N. 38 39config CPU_FREQ_STAT_DETAILS 40 bool "CPU frequency translation statistics details" 41 depends on CPU_FREQ_STAT 42 help 43 This will show detail CPU frequency translation table in sysfs file 44 system. 45 46 If in doubt, say N. 47 48choice 49 prompt "Default CPUFreq governor" 50 default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ 51 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE 52 help 53 This option sets which CPUFreq governor shall be loaded at 54 startup. If in doubt, select 'performance'. 55 56config CPU_FREQ_DEFAULT_GOV_PERFORMANCE 57 bool "performance" 58 select CPU_FREQ_GOV_PERFORMANCE 59 help 60 Use the CPUFreq governor 'performance' as default. This sets 61 the frequency statically to the highest frequency supported by 62 the CPU. 63 64config CPU_FREQ_DEFAULT_GOV_POWERSAVE 65 bool "powersave" 66 depends on EXPERT 67 select CPU_FREQ_GOV_POWERSAVE 68 help 69 Use the CPUFreq governor 'powersave' as default. This sets 70 the frequency statically to the lowest frequency supported by 71 the CPU. 72 73config CPU_FREQ_DEFAULT_GOV_USERSPACE 74 bool "userspace" 75 select CPU_FREQ_GOV_USERSPACE 76 help 77 Use the CPUFreq governor 'userspace' as default. This allows 78 you to set the CPU frequency manually or when a userspace 79 program shall be able to set the CPU dynamically without having 80 to enable the userspace governor manually. 81 82config CPU_FREQ_DEFAULT_GOV_ONDEMAND 83 bool "ondemand" 84 select CPU_FREQ_GOV_ONDEMAND 85 select CPU_FREQ_GOV_PERFORMANCE 86 help 87 Use the CPUFreq governor 'ondemand' as default. This allows 88 you to get a full dynamic frequency capable system by simply 89 loading your cpufreq low-level hardware driver. 90 Be aware that not all cpufreq drivers support the ondemand 91 governor. If unsure have a look at the help section of the 92 driver. Fallback governor will be the performance governor. 93 94config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE 95 bool "conservative" 96 select CPU_FREQ_GOV_CONSERVATIVE 97 select CPU_FREQ_GOV_PERFORMANCE 98 help 99 Use the CPUFreq governor 'conservative' as default. This allows 100 you to get a full dynamic frequency capable system by simply 101 loading your cpufreq low-level hardware driver. 102 Be aware that not all cpufreq drivers support the conservative 103 governor. If unsure have a look at the help section of the 104 driver. Fallback governor will be the performance governor. 105endchoice 106 107config CPU_FREQ_GOV_PERFORMANCE 108 tristate "'performance' governor" 109 help 110 This cpufreq governor sets the frequency statically to the 111 highest available CPU frequency. 112 113 To compile this driver as a module, choose M here: the 114 module will be called cpufreq_performance. 115 116 If in doubt, say Y. 117 118config CPU_FREQ_GOV_POWERSAVE 119 tristate "'powersave' governor" 120 help 121 This cpufreq governor sets the frequency statically to the 122 lowest available CPU frequency. 123 124 To compile this driver as a module, choose M here: the 125 module will be called cpufreq_powersave. 126 127 If in doubt, say Y. 128 129config CPU_FREQ_GOV_USERSPACE 130 tristate "'userspace' governor for userspace frequency scaling" 131 help 132 Enable this cpufreq governor when you either want to set the 133 CPU frequency manually or when a userspace program shall 134 be able to set the CPU dynamically, like on LART 135 <http://www.lartmaker.nl/>. 136 137 To compile this driver as a module, choose M here: the 138 module will be called cpufreq_userspace. 139 140 For details, take a look at <file:Documentation/cpu-freq/>. 141 142 If in doubt, say Y. 143 144config CPU_FREQ_GOV_ONDEMAND 145 tristate "'ondemand' cpufreq policy governor" 146 select CPU_FREQ_GOV_COMMON 147 help 148 'ondemand' - This driver adds a dynamic cpufreq policy governor. 149 The governor does a periodic polling and 150 changes frequency based on the CPU utilization. 151 The support for this governor depends on CPU capability to 152 do fast frequency switching (i.e, very low latency frequency 153 transitions). 154 155 To compile this driver as a module, choose M here: the 156 module will be called cpufreq_ondemand. 157 158 For details, take a look at linux/Documentation/cpu-freq. 159 160 If in doubt, say N. 161 162config CPU_FREQ_GOV_CONSERVATIVE 163 tristate "'conservative' cpufreq governor" 164 depends on CPU_FREQ 165 select CPU_FREQ_GOV_COMMON 166 help 167 'conservative' - this driver is rather similar to the 'ondemand' 168 governor both in its source code and its purpose, the difference is 169 its optimisation for better suitability in a battery powered 170 environment. The frequency is gracefully increased and decreased 171 rather than jumping to 100% when speed is required. 172 173 If you have a desktop machine then you should really be considering 174 the 'ondemand' governor instead, however if you are using a laptop, 175 PDA or even an AMD64 based computer (due to the unacceptable 176 step-by-step latency issues between the minimum and maximum frequency 177 transitions in the CPU) you will probably want to use this governor. 178 179 To compile this driver as a module, choose M here: the 180 module will be called cpufreq_conservative. 181 182 For details, take a look at linux/Documentation/cpu-freq. 183 184 If in doubt, say N. 185 186config GENERIC_CPUFREQ_CPU0 187 tristate "Generic CPU0 cpufreq driver" 188 depends on HAVE_CLK && REGULATOR && OF && THERMAL && CPU_THERMAL 189 select PM_OPP 190 help 191 This adds a generic cpufreq driver for CPU0 frequency management. 192 It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) 193 systems which share clock and voltage across all CPUs. 194 195 If in doubt, say N. 196 197menu "x86 CPU frequency scaling drivers" 198depends on X86 199source "drivers/cpufreq/Kconfig.x86" 200endmenu 201 202menu "ARM CPU frequency scaling drivers" 203depends on ARM || ARM64 204source "drivers/cpufreq/Kconfig.arm" 205endmenu 206 207menu "AVR32 CPU frequency scaling drivers" 208depends on AVR32 209 210config AVR32_AT32AP_CPUFREQ 211 bool "CPU frequency driver for AT32AP" 212 depends on PLATFORM_AT32AP 213 default n 214 help 215 This enables the CPU frequency driver for AT32AP processors. 216 If in doubt, say N. 217 218endmenu 219 220menu "CPUFreq processor drivers" 221depends on IA64 222 223config IA64_ACPI_CPUFREQ 224 tristate "ACPI Processor P-States driver" 225 depends on ACPI_PROCESSOR 226 help 227 This driver adds a CPUFreq driver which utilizes the ACPI 228 Processor Performance States. 229 230 For details, take a look at <file:Documentation/cpu-freq/>. 231 232 If in doubt, say N. 233 234endmenu 235 236menu "MIPS CPUFreq processor drivers" 237depends on MIPS 238 239config LOONGSON2_CPUFREQ 240 tristate "Loongson2 CPUFreq Driver" 241 help 242 This option adds a CPUFreq driver for loongson processors which 243 support software configurable cpu frequency. 244 245 Loongson2F and it's successors support this feature. 246 247 For details, take a look at <file:Documentation/cpu-freq/>. 248 249 If in doubt, say N. 250 251endmenu 252 253menu "PowerPC CPU frequency scaling drivers" 254depends on PPC32 || PPC64 255source "drivers/cpufreq/Kconfig.powerpc" 256endmenu 257 258menu "SPARC CPU frequency scaling drivers" 259depends on SPARC64 260config SPARC_US3_CPUFREQ 261 tristate "UltraSPARC-III CPU Frequency driver" 262 help 263 This adds the CPUFreq driver for UltraSPARC-III processors. 264 265 For details, take a look at <file:Documentation/cpu-freq>. 266 267 If in doubt, say N. 268 269config SPARC_US2E_CPUFREQ 270 tristate "UltraSPARC-IIe CPU Frequency driver" 271 help 272 This adds the CPUFreq driver for UltraSPARC-IIe processors. 273 274 For details, take a look at <file:Documentation/cpu-freq>. 275 276 If in doubt, say N. 277endmenu 278 279menu "SH CPU Frequency scaling" 280depends on SUPERH 281config SH_CPU_FREQ 282 tristate "SuperH CPU Frequency driver" 283 help 284 This adds the cpufreq driver for SuperH. Any CPU that supports 285 clock rate rounding through the clock framework can use this 286 driver. While it will make the kernel slightly larger, this is 287 harmless for CPUs that don't support rate rounding. The driver 288 will also generate a notice in the boot log before disabling 289 itself if the CPU in question is not capable of rate rounding. 290 291 For details, take a look at <file:Documentation/cpu-freq>. 292 293 If unsure, say N. 294endmenu 295 296endif 297endmenu 298