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 bool "CPU frequency transition statistics" 35 help 36 Export CPU frequency statistics information through sysfs. 37 38 If in doubt, say N. 39 40choice 41 prompt "Default CPUFreq governor" 42 default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ 43 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE 44 help 45 This option sets which CPUFreq governor shall be loaded at 46 startup. If in doubt, select 'performance'. 47 48config CPU_FREQ_DEFAULT_GOV_PERFORMANCE 49 bool "performance" 50 select CPU_FREQ_GOV_PERFORMANCE 51 help 52 Use the CPUFreq governor 'performance' as default. This sets 53 the frequency statically to the highest frequency supported by 54 the CPU. 55 56config CPU_FREQ_DEFAULT_GOV_POWERSAVE 57 bool "powersave" 58 select CPU_FREQ_GOV_POWERSAVE 59 help 60 Use the CPUFreq governor 'powersave' as default. This sets 61 the frequency statically to the lowest frequency supported by 62 the CPU. 63 64config CPU_FREQ_DEFAULT_GOV_USERSPACE 65 bool "userspace" 66 select CPU_FREQ_GOV_USERSPACE 67 help 68 Use the CPUFreq governor 'userspace' as default. This allows 69 you to set the CPU frequency manually or when a userspace 70 program shall be able to set the CPU dynamically without having 71 to enable the userspace governor manually. 72 73config CPU_FREQ_DEFAULT_GOV_ONDEMAND 74 bool "ondemand" 75 select CPU_FREQ_GOV_ONDEMAND 76 select CPU_FREQ_GOV_PERFORMANCE 77 help 78 Use the CPUFreq governor 'ondemand' as default. This allows 79 you to get a full dynamic frequency capable system by simply 80 loading your cpufreq low-level hardware driver. 81 Be aware that not all cpufreq drivers support the ondemand 82 governor. If unsure have a look at the help section of the 83 driver. Fallback governor will be the performance governor. 84 85config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE 86 bool "conservative" 87 select CPU_FREQ_GOV_CONSERVATIVE 88 select CPU_FREQ_GOV_PERFORMANCE 89 help 90 Use the CPUFreq governor 'conservative' as default. This allows 91 you to get a full dynamic frequency capable system by simply 92 loading your cpufreq low-level hardware driver. 93 Be aware that not all cpufreq drivers support the conservative 94 governor. If unsure have a look at the help section of the 95 driver. Fallback governor will be the performance governor. 96 97config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL 98 bool "schedutil" 99 depends on SMP 100 select CPU_FREQ_GOV_SCHEDUTIL 101 select CPU_FREQ_GOV_PERFORMANCE 102 help 103 Use the 'schedutil' CPUFreq governor by default. If unsure, 104 have a look at the help section of that governor. The fallback 105 governor will be 'performance'. 106 107endchoice 108 109config CPU_FREQ_GOV_PERFORMANCE 110 tristate "'performance' governor" 111 help 112 This cpufreq governor sets the frequency statically to the 113 highest available CPU frequency. 114 115 To compile this driver as a module, choose M here: the 116 module will be called cpufreq_performance. 117 118 If in doubt, say Y. 119 120config CPU_FREQ_GOV_POWERSAVE 121 tristate "'powersave' governor" 122 help 123 This cpufreq governor sets the frequency statically to the 124 lowest available CPU frequency. 125 126 To compile this driver as a module, choose M here: the 127 module will be called cpufreq_powersave. 128 129 If in doubt, say Y. 130 131config CPU_FREQ_GOV_USERSPACE 132 tristate "'userspace' governor for userspace frequency scaling" 133 help 134 Enable this cpufreq governor when you either want to set the 135 CPU frequency manually or when a userspace program shall 136 be able to set the CPU dynamically, like on LART 137 <http://www.lartmaker.nl/>. 138 139 To compile this driver as a module, choose M here: the 140 module will be called cpufreq_userspace. 141 142 For details, take a look at <file:Documentation/cpu-freq/>. 143 144 If in doubt, say Y. 145 146config CPU_FREQ_GOV_ONDEMAND 147 tristate "'ondemand' cpufreq policy governor" 148 select CPU_FREQ_GOV_COMMON 149 help 150 'ondemand' - This driver adds a dynamic cpufreq policy governor. 151 The governor does a periodic polling and 152 changes frequency based on the CPU utilization. 153 The support for this governor depends on CPU capability to 154 do fast frequency switching (i.e, very low latency frequency 155 transitions). 156 157 To compile this driver as a module, choose M here: the 158 module will be called cpufreq_ondemand. 159 160 For details, take a look at linux/Documentation/cpu-freq. 161 162 If in doubt, say N. 163 164config CPU_FREQ_GOV_CONSERVATIVE 165 tristate "'conservative' cpufreq governor" 166 depends on CPU_FREQ 167 select CPU_FREQ_GOV_COMMON 168 help 169 'conservative' - this driver is rather similar to the 'ondemand' 170 governor both in its source code and its purpose, the difference is 171 its optimisation for better suitability in a battery powered 172 environment. The frequency is gracefully increased and decreased 173 rather than jumping to 100% when speed is required. 174 175 If you have a desktop machine then you should really be considering 176 the 'ondemand' governor instead, however if you are using a laptop, 177 PDA or even an AMD64 based computer (due to the unacceptable 178 step-by-step latency issues between the minimum and maximum frequency 179 transitions in the CPU) you will probably want to use this governor. 180 181 To compile this driver as a module, choose M here: the 182 module will be called cpufreq_conservative. 183 184 For details, take a look at linux/Documentation/cpu-freq. 185 186 If in doubt, say N. 187 188config CPU_FREQ_GOV_SCHEDUTIL 189 bool "'schedutil' cpufreq policy governor" 190 depends on CPU_FREQ && SMP 191 select CPU_FREQ_GOV_ATTR_SET 192 select IRQ_WORK 193 help 194 This governor makes decisions based on the utilization data provided 195 by the scheduler. It sets the CPU frequency to be proportional to 196 the utilization/capacity ratio coming from the scheduler. If the 197 utilization is frequency-invariant, the new frequency is also 198 proportional to the maximum available frequency. If that is not the 199 case, it is proportional to the current frequency of the CPU. The 200 frequency tipping point is at utilization/capacity equal to 80% in 201 both cases. 202 203 If in doubt, say N. 204 205comment "CPU frequency scaling drivers" 206 207config CPUFREQ_DT 208 tristate "Generic DT based cpufreq driver" 209 depends on HAVE_CLK && OF 210 # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y: 211 depends on !CPU_THERMAL || THERMAL 212 select CPUFREQ_DT_PLATDEV 213 select PM_OPP 214 help 215 This adds a generic DT based cpufreq driver for frequency management. 216 It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) 217 systems. 218 219 If in doubt, say N. 220 221config CPUFREQ_DT_PLATDEV 222 bool 223 help 224 This adds a generic DT based cpufreq platdev driver for frequency 225 management. This creates a 'cpufreq-dt' platform device, on the 226 supported platforms. 227 228 If in doubt, say N. 229 230if X86 231source "drivers/cpufreq/Kconfig.x86" 232endif 233 234if ARM || ARM64 235source "drivers/cpufreq/Kconfig.arm" 236endif 237 238if PPC32 || PPC64 239source "drivers/cpufreq/Kconfig.powerpc" 240endif 241 242if AVR32 243config AVR32_AT32AP_CPUFREQ 244 bool "CPU frequency driver for AT32AP" 245 depends on PLATFORM_AT32AP 246 default n 247 help 248 This enables the CPU frequency driver for AT32AP processors. 249 If in doubt, say N. 250endif 251 252if IA64 253config IA64_ACPI_CPUFREQ 254 tristate "ACPI Processor P-States driver" 255 depends on ACPI_PROCESSOR 256 help 257 This driver adds a CPUFreq driver which utilizes the ACPI 258 Processor Performance States. 259 260 For details, take a look at <file:Documentation/cpu-freq/>. 261 262 If in doubt, say N. 263endif 264 265if MIPS 266config BMIPS_CPUFREQ 267 tristate "BMIPS CPUfreq Driver" 268 help 269 This option adds a CPUfreq driver for BMIPS processors with 270 support for configurable CPU frequency. 271 272 For now, BMIPS5 chips are supported (such as the Broadcom 7425). 273 274 If in doubt, say N. 275 276config LOONGSON2_CPUFREQ 277 tristate "Loongson2 CPUFreq Driver" 278 help 279 This option adds a CPUFreq driver for loongson processors which 280 support software configurable cpu frequency. 281 282 Loongson2F and it's successors support this feature. 283 284 For details, take a look at <file:Documentation/cpu-freq/>. 285 286 If in doubt, say N. 287 288config LOONGSON1_CPUFREQ 289 tristate "Loongson1 CPUFreq Driver" 290 help 291 This option adds a CPUFreq driver for loongson1 processors which 292 support software configurable cpu frequency. 293 294 For details, take a look at <file:Documentation/cpu-freq/>. 295 296 If in doubt, say N. 297endif 298 299if SPARC64 300config SPARC_US3_CPUFREQ 301 tristate "UltraSPARC-III CPU Frequency driver" 302 help 303 This adds the CPUFreq driver for UltraSPARC-III processors. 304 305 For details, take a look at <file:Documentation/cpu-freq>. 306 307 If in doubt, say N. 308 309config SPARC_US2E_CPUFREQ 310 tristate "UltraSPARC-IIe CPU Frequency driver" 311 help 312 This adds the CPUFreq driver for UltraSPARC-IIe processors. 313 314 For details, take a look at <file:Documentation/cpu-freq>. 315 316 If in doubt, say N. 317endif 318 319if SUPERH 320config SH_CPU_FREQ 321 tristate "SuperH CPU Frequency driver" 322 help 323 This adds the cpufreq driver for SuperH. Any CPU that supports 324 clock rate rounding through the clock framework can use this 325 driver. While it will make the kernel slightly larger, this is 326 harmless for CPUs that don't support rate rounding. The driver 327 will also generate a notice in the boot log before disabling 328 itself if the CPU in question is not capable of rate rounding. 329 330 For details, take a look at <file:Documentation/cpu-freq>. 331 332 If unsure, say N. 333endif 334 335config QORIQ_CPUFREQ 336 tristate "CPU frequency scaling driver for Freescale QorIQ SoCs" 337 depends on OF && COMMON_CLK && (PPC_E500MC || ARM || ARM64) 338 depends on !CPU_THERMAL || THERMAL 339 select CLK_QORIQ 340 help 341 This adds the CPUFreq driver support for Freescale QorIQ SoCs 342 which are capable of changing the CPU's frequency dynamically. 343 344endif 345endmenu 346