drivers/cpufreq/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 menu "CPU Frequency scaling"
   3
   4 config CPU_FREQ
   5         bool "CPU Frequency scaling"
   6         select SRCU
   7         help
   8           CPU Frequency scaling allows you to change the clock speed of
   9           CPUs on the fly. This is a nice method to save power, because
  10           the lower the CPU clock speed, the less power the CPU consumes.
  11
  12           Note that this driver doesn't automatically change the CPU
  13           clock speed, you need to either enable a dynamic cpufreq governor
  14           (see below) after boot, or use a userspace tool.
  15
  16           For details, take a look at <file:Documentation/cpu-freq>.
  17
  18           If in doubt, say N.
  19
  20 if CPU_FREQ
  21
  22 config CPU_FREQ_GOV_ATTR_SET
  23         bool
  24
  25 config CPU_FREQ_GOV_COMMON
  26         select CPU_FREQ_GOV_ATTR_SET
  27         select IRQ_WORK
  28         bool
  29
  30 config CPU_FREQ_STAT
  31         bool "CPU frequency transition statistics"
  32         help
  33           Export CPU frequency statistics information through sysfs.
  34
  35           If in doubt, say N.
  36
  37 choice
  38         prompt "Default CPUFreq governor"
  39         default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
  40         default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE
  41         default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if X86_INTEL_PSTATE && SMP
  42         default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  43         help
  44           This option sets which CPUFreq governor shall be loaded at
  45           startup. If in doubt, use the default setting.
  46
  47 config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  48         bool "performance"
  49         select CPU_FREQ_GOV_PERFORMANCE
  50         help
  51           Use the CPUFreq governor 'performance' as default. This sets
  52           the frequency statically to the highest frequency supported by
  53           the CPU.
  54
  55 config CPU_FREQ_DEFAULT_GOV_POWERSAVE
  56         bool "powersave"
  57         select CPU_FREQ_GOV_POWERSAVE
  58         help
  59           Use the CPUFreq governor 'powersave' as default. This sets
  60           the frequency statically to the lowest frequency supported by
  61           the CPU.
  62
  63 config CPU_FREQ_DEFAULT_GOV_USERSPACE
  64         bool "userspace"
  65         select CPU_FREQ_GOV_USERSPACE
  66         help
  67           Use the CPUFreq governor 'userspace' as default. This allows
  68           you to set the CPU frequency manually or when a userspace
  69           program shall be able to set the CPU dynamically without having
  70           to enable the userspace governor manually.
  71
  72 config CPU_FREQ_DEFAULT_GOV_ONDEMAND
  73         bool "ondemand"
  74         select CPU_FREQ_GOV_ONDEMAND
  75         select CPU_FREQ_GOV_PERFORMANCE
  76         help
  77           Use the CPUFreq governor 'ondemand' as default. This allows
  78           you to get a full dynamic frequency capable system by simply
  79           loading your cpufreq low-level hardware driver.
  80           Be aware that not all cpufreq drivers support the ondemand
  81           governor. If unsure have a look at the help section of the
  82           driver. Fallback governor will be the performance governor.
  83
  84 config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
  85         bool "conservative"
  86         select CPU_FREQ_GOV_CONSERVATIVE
  87         select CPU_FREQ_GOV_PERFORMANCE
  88         help
  89           Use the CPUFreq governor 'conservative' as default. This allows
  90           you to get a full dynamic frequency capable system by simply
  91           loading your cpufreq low-level hardware driver.
  92           Be aware that not all cpufreq drivers support the conservative
  93           governor. If unsure have a look at the help section of the
  94           driver. Fallback governor will be the performance governor.
  95
  96 config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
  97         bool "schedutil"
  98         depends on SMP
  99         select CPU_FREQ_GOV_SCHEDUTIL
 100         select CPU_FREQ_GOV_PERFORMANCE
 101         help
 102           Use the 'schedutil' CPUFreq governor by default. If unsure,
 103           have a look at the help section of that governor. The fallback
 104           governor will be 'performance'.
 105
 106 endchoice
 107
 108 config CPU_FREQ_GOV_PERFORMANCE
 109         tristate "'performance' governor"
 110         help
 111           This cpufreq governor sets the frequency statically to the
 112           highest available CPU frequency.
 113
 114           To compile this driver as a module, choose M here: the
 115           module will be called cpufreq_performance.
 116
 117           If in doubt, say Y.
 118
 119 config CPU_FREQ_GOV_POWERSAVE
 120         tristate "'powersave' governor"
 121         help
 122           This cpufreq governor sets the frequency statically to the
 123           lowest available CPU frequency.
 124
 125           To compile this driver as a module, choose M here: the
 126           module will be called cpufreq_powersave.
 127
 128           If in doubt, say Y.
 129
 130 config CPU_FREQ_GOV_USERSPACE
 131         tristate "'userspace' governor for userspace frequency scaling"
 132         help
 133           Enable this cpufreq governor when you either want to set the
 134           CPU frequency manually or when a userspace program shall
 135           be able to set the CPU dynamically, like on LART
 136           <http://www.lartmaker.nl/>.
 137
 138           To compile this driver as a module, choose M here: the
 139           module will be called cpufreq_userspace.
 140
 141           For details, take a look at <file:Documentation/cpu-freq/>.
 142
 143           If in doubt, say Y.
 144
 145 config CPU_FREQ_GOV_ONDEMAND
 146         tristate "'ondemand' cpufreq policy governor"
 147         select CPU_FREQ_GOV_COMMON
 148         help
 149           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 150           The governor does a periodic polling and
 151           changes frequency based on the CPU utilization.
 152           The support for this governor depends on CPU capability to
 153           do fast frequency switching (i.e, very low latency frequency
 154           transitions).
 155
 156           To compile this driver as a module, choose M here: the
 157           module will be called cpufreq_ondemand.
 158
 159           For details, take a look at linux/Documentation/cpu-freq.
 160
 161           If in doubt, say N.
 162
 163 config CPU_FREQ_GOV_CONSERVATIVE
 164         tristate "'conservative' cpufreq governor"
 165         depends on CPU_FREQ
 166         select CPU_FREQ_GOV_COMMON
 167         help
 168           'conservative' - this driver is rather similar to the 'ondemand'
 169           governor both in its source code and its purpose, the difference is
 170           its optimisation for better suitability in a battery powered
 171           environment.  The frequency is gracefully increased and decreased
 172           rather than jumping to 100% when speed is required.
 173
 174           If you have a desktop machine then you should really be considering
 175           the 'ondemand' governor instead, however if you are using a laptop,
 176           PDA or even an AMD64 based computer (due to the unacceptable
 177           step-by-step latency issues between the minimum and maximum frequency
 178           transitions in the CPU) you will probably want to use this governor.
 179
 180           To compile this driver as a module, choose M here: the
 181           module will be called cpufreq_conservative.
 182
 183           For details, take a look at linux/Documentation/cpu-freq.
 184
 185           If in doubt, say N.
 186
 187 config CPU_FREQ_GOV_SCHEDUTIL
 188         bool "'schedutil' cpufreq policy governor"
 189         depends on CPU_FREQ && SMP
 190         select CPU_FREQ_GOV_ATTR_SET
 191         select IRQ_WORK
 192         help
 193           This governor makes decisions based on the utilization data provided
 194           by the scheduler.  It sets the CPU frequency to be proportional to
 195           the utilization/capacity ratio coming from the scheduler.  If the
 196           utilization is frequency-invariant, the new frequency is also
 197           proportional to the maximum available frequency.  If that is not the
 198           case, it is proportional to the current frequency of the CPU.  The
 199           frequency tipping point is at utilization/capacity equal to 80% in
 200           both cases.
 201
 202           If in doubt, say N.
 203
 204 comment "CPU frequency scaling drivers"
 205
 206 config CPUFREQ_DT
 207         tristate "Generic DT based cpufreq driver"
 208         depends on HAVE_CLK && OF
 209         select CPUFREQ_DT_PLATDEV
 210         select PM_OPP
 211         help
 212           This adds a generic DT based cpufreq driver for frequency management.
 213           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 214           systems.
 215
 216           If in doubt, say N.
 217
 218 config CPUFREQ_DT_PLATDEV
 219         bool
 220         help
 221           This adds a generic DT based cpufreq platdev driver for frequency
 222           management.  This creates a 'cpufreq-dt' platform device, on the
 223           supported platforms.
 224
 225           If in doubt, say N.
 226
 227 if X86
 228 source "drivers/cpufreq/Kconfig.x86"
 229 endif
 230
 231 if ARM || ARM64
 232 source "drivers/cpufreq/Kconfig.arm"
 233 endif
 234
 235 if PPC32 || PPC64
 236 source "drivers/cpufreq/Kconfig.powerpc"
 237 endif
 238
 239 if IA64
 240 config IA64_ACPI_CPUFREQ
 241         tristate "ACPI Processor P-States driver"
 242         depends on ACPI_PROCESSOR
 243         help
 244         This driver adds a CPUFreq driver which utilizes the ACPI
 245         Processor Performance States.
 246
 247         For details, take a look at <file:Documentation/cpu-freq/>.
 248
 249         If in doubt, say N.
 250 endif
 251
 252 if MIPS
 253 config BMIPS_CPUFREQ
 254         tristate "BMIPS CPUfreq Driver"
 255         help
 256           This option adds a CPUfreq driver for BMIPS processors with
 257           support for configurable CPU frequency.
 258
 259           For now, BMIPS5 chips are supported (such as the Broadcom 7425).
 260
 261           If in doubt, say N.
 262
 263 config LOONGSON2_CPUFREQ
 264         tristate "Loongson2 CPUFreq Driver"
 265         depends on LEMOTE_MACH2F
 266         help
 267           This option adds a CPUFreq driver for loongson processors which
 268           support software configurable cpu frequency.
 269
 270           Loongson2F and it's successors support this feature.
 271
 272           For details, take a look at <file:Documentation/cpu-freq/>.
 273
 274           If in doubt, say N.
 275
 276 config LOONGSON1_CPUFREQ
 277         tristate "Loongson1 CPUFreq Driver"
 278         depends on LOONGSON1_LS1B
 279         help
 280           This option adds a CPUFreq driver for loongson1 processors which
 281           support software configurable cpu frequency.
 282
 283           For details, take a look at <file:Documentation/cpu-freq/>.
 284
 285           If in doubt, say N.
 286 endif
 287
 288 if SPARC64
 289 config SPARC_US3_CPUFREQ
 290         tristate "UltraSPARC-III CPU Frequency driver"
 291         help
 292           This adds the CPUFreq driver for UltraSPARC-III processors.
 293
 294           For details, take a look at <file:Documentation/cpu-freq>.
 295
 296           If in doubt, say N.
 297
 298 config SPARC_US2E_CPUFREQ
 299         tristate "UltraSPARC-IIe CPU Frequency driver"
 300         help
 301           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 302
 303           For details, take a look at <file:Documentation/cpu-freq>.
 304
 305           If in doubt, say N.
 306 endif
 307
 308 if SUPERH
 309 config SH_CPU_FREQ
 310         tristate "SuperH CPU Frequency driver"
 311         help
 312           This adds the cpufreq driver for SuperH. Any CPU that supports
 313           clock rate rounding through the clock framework can use this
 314           driver. While it will make the kernel slightly larger, this is
 315           harmless for CPUs that don't support rate rounding. The driver
 316           will also generate a notice in the boot log before disabling
 317           itself if the CPU in question is not capable of rate rounding.
 318
 319           For details, take a look at <file:Documentation/cpu-freq>.
 320
 321           If unsure, say N.
 322 endif
 323
 324 config QORIQ_CPUFREQ
 325         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 326         depends on OF && COMMON_CLK && (PPC_E500MC || ARM || ARM64)
 327         select CLK_QORIQ
 328         help
 329           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 330           which are capable of changing the CPU's frequency dynamically.
 331
 332 endif
 333 endmenu