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_COMMON 22 bool 23 24config CPU_FREQ_BOOST_SW 25 bool 26 depends on THERMAL 27 28config CPU_FREQ_STAT 29 tristate "CPU frequency translation statistics" 30 default y 31 help 32 This driver exports CPU frequency statistics information through sysfs 33 file system. 34 35 To compile this driver as a module, choose M here: the 36 module will be called cpufreq_stats. 37 38 If in doubt, say N. 39 40config CPU_FREQ_STAT_DETAILS 41 bool "CPU frequency translation statistics details" 42 depends on CPU_FREQ_STAT 43 help 44 This will show detail CPU frequency translation table in sysfs file 45 system. 46 47 If in doubt, say N. 48 49choice 50 prompt "Default CPUFreq governor" 51 default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ 52 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE 53 help 54 This option sets which CPUFreq governor shall be loaded at 55 startup. If in doubt, select 'performance'. 56 57config CPU_FREQ_DEFAULT_GOV_PERFORMANCE 58 bool "performance" 59 select CPU_FREQ_GOV_PERFORMANCE 60 help 61 Use the CPUFreq governor 'performance' as default. This sets 62 the frequency statically to the highest frequency supported by 63 the CPU. 64 65config CPU_FREQ_DEFAULT_GOV_POWERSAVE 66 bool "powersave" 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 186comment "CPU frequency scaling drivers" 187 188config CPUFREQ_DT 189 tristate "Generic DT based cpufreq driver" 190 depends on HAVE_CLK && OF 191 # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y: 192 depends on !CPU_THERMAL || THERMAL 193 select PM_OPP 194 help 195 This adds a generic DT based cpufreq driver for frequency management. 196 It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) 197 systems which share clock and voltage across all CPUs. 198 199 If in doubt, say N. 200 201if X86 202source "drivers/cpufreq/Kconfig.x86" 203endif 204 205if ARM || ARM64 206source "drivers/cpufreq/Kconfig.arm" 207endif 208 209if PPC32 || PPC64 210source "drivers/cpufreq/Kconfig.powerpc" 211endif 212 213if AVR32 214config AVR32_AT32AP_CPUFREQ 215 bool "CPU frequency driver for AT32AP" 216 depends on PLATFORM_AT32AP 217 default n 218 help 219 This enables the CPU frequency driver for AT32AP processors. 220 If in doubt, say N. 221endif 222 223if IA64 224config IA64_ACPI_CPUFREQ 225 tristate "ACPI Processor P-States driver" 226 depends on ACPI_PROCESSOR 227 help 228 This driver adds a CPUFreq driver which utilizes the ACPI 229 Processor Performance States. 230 231 For details, take a look at <file:Documentation/cpu-freq/>. 232 233 If in doubt, say N. 234endif 235 236if MIPS 237config LOONGSON2_CPUFREQ 238 tristate "Loongson2 CPUFreq Driver" 239 help 240 This option adds a CPUFreq driver for loongson processors which 241 support software configurable cpu frequency. 242 243 Loongson2F and it's successors support this feature. 244 245 For details, take a look at <file:Documentation/cpu-freq/>. 246 247 If in doubt, say N. 248 249config LOONGSON1_CPUFREQ 250 tristate "Loongson1 CPUFreq Driver" 251 help 252 This option adds a CPUFreq driver for loongson1 processors which 253 support software configurable cpu frequency. 254 255 For details, take a look at <file:Documentation/cpu-freq/>. 256 257 If in doubt, say N. 258endif 259 260if SPARC64 261config SPARC_US3_CPUFREQ 262 tristate "UltraSPARC-III CPU Frequency driver" 263 help 264 This adds the CPUFreq driver for UltraSPARC-III processors. 265 266 For details, take a look at <file:Documentation/cpu-freq>. 267 268 If in doubt, say N. 269 270config SPARC_US2E_CPUFREQ 271 tristate "UltraSPARC-IIe CPU Frequency driver" 272 help 273 This adds the CPUFreq driver for UltraSPARC-IIe processors. 274 275 For details, take a look at <file:Documentation/cpu-freq>. 276 277 If in doubt, say N. 278endif 279 280if 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. 294endif 295 296config QORIQ_CPUFREQ 297 tristate "CPU frequency scaling driver for Freescale QorIQ SoCs" 298 depends on OF && COMMON_CLK && (PPC_E500MC || ARM) 299 select CLK_QORIQ 300 help 301 This adds the CPUFreq driver support for Freescale QorIQ SoCs 302 which are capable of changing the CPU's frequency dynamically. 303 304endif 305endmenu 306