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