1menu "CPU Frequency scaling" 2 3config CPU_FREQ 4 bool "CPU Frequency scaling" 5 select SRCU 6 help 7 CPU Frequency scaling allows you to change the clock speed of 8 CPUs on the fly. This is a nice method to save power, because 9 the lower the CPU clock speed, the less power the CPU consumes. 10 11 Note that this driver doesn't automatically change the CPU 12 clock speed, you need to either enable a dynamic cpufreq governor 13 (see below) after boot, or use a userspace tool. 14 15 For details, take a look at <file:Documentation/cpu-freq>. 16 17 If in doubt, say N. 18 19if CPU_FREQ 20 21config CPU_FREQ_GOV_ATTR_SET 22 bool 23 24config CPU_FREQ_GOV_COMMON 25 select CPU_FREQ_GOV_ATTR_SET 26 select IRQ_WORK 27 bool 28 29config CPU_FREQ_BOOST_SW 30 bool 31 depends on THERMAL 32 33config CPU_FREQ_STAT 34 tristate "CPU frequency translation statistics" 35 default y 36 help 37 This driver exports CPU frequency statistics information through sysfs 38 file system. 39 40 To compile this driver as a module, choose M here: the 41 module will be called cpufreq_stats. 42 43 If in doubt, say N. 44 45config CPU_FREQ_STAT_DETAILS 46 bool "CPU frequency translation statistics details" 47 depends on CPU_FREQ_STAT 48 help 49 This will show detail CPU frequency translation table in sysfs file 50 system. 51 52 If in doubt, say N. 53 54choice 55 prompt "Default CPUFreq governor" 56 default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ 57 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE 58 help 59 This option sets which CPUFreq governor shall be loaded at 60 startup. If in doubt, select 'performance'. 61 62config CPU_FREQ_DEFAULT_GOV_PERFORMANCE 63 bool "performance" 64 select CPU_FREQ_GOV_PERFORMANCE 65 help 66 Use the CPUFreq governor 'performance' as default. This sets 67 the frequency statically to the highest frequency supported by 68 the CPU. 69 70config CPU_FREQ_DEFAULT_GOV_POWERSAVE 71 bool "powersave" 72 select CPU_FREQ_GOV_POWERSAVE 73 help 74 Use the CPUFreq governor 'powersave' as default. This sets 75 the frequency statically to the lowest frequency supported by 76 the CPU. 77 78config CPU_FREQ_DEFAULT_GOV_USERSPACE 79 bool "userspace" 80 select CPU_FREQ_GOV_USERSPACE 81 help 82 Use the CPUFreq governor 'userspace' as default. This allows 83 you to set the CPU frequency manually or when a userspace 84 program shall be able to set the CPU dynamically without having 85 to enable the userspace governor manually. 86 87config CPU_FREQ_DEFAULT_GOV_ONDEMAND 88 bool "ondemand" 89 select CPU_FREQ_GOV_ONDEMAND 90 select CPU_FREQ_GOV_PERFORMANCE 91 help 92 Use the CPUFreq governor 'ondemand' as default. This allows 93 you to get a full dynamic frequency capable system by simply 94 loading your cpufreq low-level hardware driver. 95 Be aware that not all cpufreq drivers support the ondemand 96 governor. If unsure have a look at the help section of the 97 driver. Fallback governor will be the performance governor. 98 99config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE 100 bool "conservative" 101 select CPU_FREQ_GOV_CONSERVATIVE 102 select CPU_FREQ_GOV_PERFORMANCE 103 help 104 Use the CPUFreq governor 'conservative' as default. This allows 105 you to get a full dynamic frequency capable system by simply 106 loading your cpufreq low-level hardware driver. 107 Be aware that not all cpufreq drivers support the conservative 108 governor. If unsure have a look at the help section of the 109 driver. Fallback governor will be the performance governor. 110 111config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL 112 bool "schedutil" 113 depends on SMP 114 select CPU_FREQ_GOV_SCHEDUTIL 115 select CPU_FREQ_GOV_PERFORMANCE 116 help 117 Use the 'schedutil' CPUFreq governor by default. If unsure, 118 have a look at the help section of that governor. The fallback 119 governor will be 'performance'. 120 121endchoice 122 123config CPU_FREQ_GOV_PERFORMANCE 124 tristate "'performance' governor" 125 help 126 This cpufreq governor sets the frequency statically to the 127 highest available CPU frequency. 128 129 To compile this driver as a module, choose M here: the 130 module will be called cpufreq_performance. 131 132 If in doubt, say Y. 133 134config CPU_FREQ_GOV_POWERSAVE 135 tristate "'powersave' governor" 136 help 137 This cpufreq governor sets the frequency statically to the 138 lowest available CPU frequency. 139 140 To compile this driver as a module, choose M here: the 141 module will be called cpufreq_powersave. 142 143 If in doubt, say Y. 144 145config CPU_FREQ_GOV_USERSPACE 146 tristate "'userspace' governor for userspace frequency scaling" 147 help 148 Enable this cpufreq governor when you either want to set the 149 CPU frequency manually or when a userspace program shall 150 be able to set the CPU dynamically, like on LART 151 <http://www.lartmaker.nl/>. 152 153 To compile this driver as a module, choose M here: the 154 module will be called cpufreq_userspace. 155 156 For details, take a look at <file:Documentation/cpu-freq/>. 157 158 If in doubt, say Y. 159 160config CPU_FREQ_GOV_ONDEMAND 161 tristate "'ondemand' cpufreq policy governor" 162 select CPU_FREQ_GOV_COMMON 163 help 164 'ondemand' - This driver adds a dynamic cpufreq policy governor. 165 The governor does a periodic polling and 166 changes frequency based on the CPU utilization. 167 The support for this governor depends on CPU capability to 168 do fast frequency switching (i.e, very low latency frequency 169 transitions). 170 171 To compile this driver as a module, choose M here: the 172 module will be called cpufreq_ondemand. 173 174 For details, take a look at linux/Documentation/cpu-freq. 175 176 If in doubt, say N. 177 178config CPU_FREQ_GOV_CONSERVATIVE 179 tristate "'conservative' cpufreq governor" 180 depends on CPU_FREQ 181 select CPU_FREQ_GOV_COMMON 182 help 183 'conservative' - this driver is rather similar to the 'ondemand' 184 governor both in its source code and its purpose, the difference is 185 its optimisation for better suitability in a battery powered 186 environment. The frequency is gracefully increased and decreased 187 rather than jumping to 100% when speed is required. 188 189 If you have a desktop machine then you should really be considering 190 the 'ondemand' governor instead, however if you are using a laptop, 191 PDA or even an AMD64 based computer (due to the unacceptable 192 step-by-step latency issues between the minimum and maximum frequency 193 transitions in the CPU) you will probably want to use this governor. 194 195 To compile this driver as a module, choose M here: the 196 module will be called cpufreq_conservative. 197 198 For details, take a look at linux/Documentation/cpu-freq. 199 200 If in doubt, say N. 201 202config CPU_FREQ_GOV_SCHEDUTIL 203 tristate "'schedutil' cpufreq policy governor" 204 depends on CPU_FREQ && SMP 205 select CPU_FREQ_GOV_ATTR_SET 206 select IRQ_WORK 207 help 208 This governor makes decisions based on the utilization data provided 209 by the scheduler. It sets the CPU frequency to be proportional to 210 the utilization/capacity ratio coming from the scheduler. If the 211 utilization is frequency-invariant, the new frequency is also 212 proportional to the maximum available frequency. If that is not the 213 case, it is proportional to the current frequency of the CPU. The 214 frequency tipping point is at utilization/capacity equal to 80% in 215 both cases. 216 217 To compile this driver as a module, choose M here: the module will 218 be called cpufreq_schedutil. 219 220 If in doubt, say N. 221 222comment "CPU frequency scaling drivers" 223 224config CPUFREQ_DT 225 tristate "Generic DT based cpufreq driver" 226 depends on HAVE_CLK && OF 227 # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y: 228 depends on !CPU_THERMAL || THERMAL 229 select CPUFREQ_DT_PLATDEV 230 select PM_OPP 231 help 232 This adds a generic DT based cpufreq driver for frequency management. 233 It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) 234 systems which share clock and voltage across all CPUs. 235 236 If in doubt, say N. 237 238config CPUFREQ_DT_PLATDEV 239 bool 240 help 241 This adds a generic DT based cpufreq platdev driver for frequency 242 management. This creates a 'cpufreq-dt' platform device, on the 243 supported platforms. 244 245 If in doubt, say N. 246 247if X86 248source "drivers/cpufreq/Kconfig.x86" 249endif 250 251if ARM || ARM64 252source "drivers/cpufreq/Kconfig.arm" 253endif 254 255if PPC32 || PPC64 256source "drivers/cpufreq/Kconfig.powerpc" 257endif 258 259if AVR32 260config AVR32_AT32AP_CPUFREQ 261 bool "CPU frequency driver for AT32AP" 262 depends on PLATFORM_AT32AP 263 default n 264 help 265 This enables the CPU frequency driver for AT32AP processors. 266 If in doubt, say N. 267endif 268 269if IA64 270config IA64_ACPI_CPUFREQ 271 tristate "ACPI Processor P-States driver" 272 depends on ACPI_PROCESSOR 273 help 274 This driver adds a CPUFreq driver which utilizes the ACPI 275 Processor Performance States. 276 277 For details, take a look at <file:Documentation/cpu-freq/>. 278 279 If in doubt, say N. 280endif 281 282if MIPS 283config LOONGSON2_CPUFREQ 284 tristate "Loongson2 CPUFreq Driver" 285 help 286 This option adds a CPUFreq driver for loongson processors which 287 support software configurable cpu frequency. 288 289 Loongson2F and it's successors support this feature. 290 291 For details, take a look at <file:Documentation/cpu-freq/>. 292 293 If in doubt, say N. 294 295config LOONGSON1_CPUFREQ 296 tristate "Loongson1 CPUFreq Driver" 297 help 298 This option adds a CPUFreq driver for loongson1 processors which 299 support software configurable cpu frequency. 300 301 For details, take a look at <file:Documentation/cpu-freq/>. 302 303 If in doubt, say N. 304endif 305 306if SPARC64 307config SPARC_US3_CPUFREQ 308 tristate "UltraSPARC-III CPU Frequency driver" 309 help 310 This adds the CPUFreq driver for UltraSPARC-III processors. 311 312 For details, take a look at <file:Documentation/cpu-freq>. 313 314 If in doubt, say N. 315 316config SPARC_US2E_CPUFREQ 317 tristate "UltraSPARC-IIe CPU Frequency driver" 318 help 319 This adds the CPUFreq driver for UltraSPARC-IIe processors. 320 321 For details, take a look at <file:Documentation/cpu-freq>. 322 323 If in doubt, say N. 324endif 325 326if SUPERH 327config SH_CPU_FREQ 328 tristate "SuperH CPU Frequency driver" 329 help 330 This adds the cpufreq driver for SuperH. Any CPU that supports 331 clock rate rounding through the clock framework can use this 332 driver. While it will make the kernel slightly larger, this is 333 harmless for CPUs that don't support rate rounding. The driver 334 will also generate a notice in the boot log before disabling 335 itself if the CPU in question is not capable of rate rounding. 336 337 For details, take a look at <file:Documentation/cpu-freq>. 338 339 If unsure, say N. 340endif 341 342config QORIQ_CPUFREQ 343 tristate "CPU frequency scaling driver for Freescale QorIQ SoCs" 344 depends on OF && COMMON_CLK && (PPC_E500MC || ARM) 345 depends on !CPU_THERMAL || THERMAL 346 select CLK_QORIQ 347 help 348 This adds the CPUFreq driver support for Freescale QorIQ SoCs 349 which are capable of changing the CPU's frequency dynamically. 350 351endif 352endmenu 353