drivers/cpufreq/Kconfig

   1 menu "CPU Frequency scaling"
   2
   3 config 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
  19 if CPU_FREQ
  20
  21 config CPU_FREQ_GOV_ATTR_SET
  22         bool
  23
  24 config CPU_FREQ_GOV_COMMON
  25         select CPU_FREQ_GOV_ATTR_SET
  26         select IRQ_WORK
  27         bool
  28
  29 config CPU_FREQ_BOOST_SW
  30         bool
  31         depends on THERMAL
  32
  33 config 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
  40 config 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
  48 choice
  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
  56 config 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
  64 config 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
  72 config 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
  81 config 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
  93 config 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
 105 config 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
 115 endchoice
 116
 117 config 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
 128 config 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
 139 config 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
 154 config 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
 172 config 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
 196 config CPU_FREQ_GOV_SCHEDUTIL
 197         tristate "'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           To compile this driver as a module, choose M here: the module will
 212           be called cpufreq_schedutil.
 213
 214           If in doubt, say N.
 215
 216 comment "CPU frequency scaling drivers"
 217
 218 config CPUFREQ_DT
 219         tristate "Generic DT based cpufreq driver"
 220         depends on HAVE_CLK && OF
 221         # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 222         depends on !CPU_THERMAL || THERMAL
 223         select CPUFREQ_DT_PLATDEV
 224         select PM_OPP
 225         help
 226           This adds a generic DT based cpufreq driver for frequency management.
 227           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 228           systems which share clock and voltage across all CPUs.
 229
 230           If in doubt, say N.
 231
 232 config CPUFREQ_DT_PLATDEV
 233         bool
 234         help
 235           This adds a generic DT based cpufreq platdev driver for frequency
 236           management.  This creates a 'cpufreq-dt' platform device, on the
 237           supported platforms.
 238
 239           If in doubt, say N.
 240
 241 if X86
 242 source "drivers/cpufreq/Kconfig.x86"
 243 endif
 244
 245 if ARM || ARM64
 246 source "drivers/cpufreq/Kconfig.arm"
 247 endif
 248
 249 if PPC32 || PPC64
 250 source "drivers/cpufreq/Kconfig.powerpc"
 251 endif
 252
 253 if AVR32
 254 config AVR32_AT32AP_CPUFREQ
 255         bool "CPU frequency driver for AT32AP"
 256         depends on PLATFORM_AT32AP
 257         default n
 258         help
 259           This enables the CPU frequency driver for AT32AP processors.
 260           If in doubt, say N.
 261 endif
 262
 263 if IA64
 264 config IA64_ACPI_CPUFREQ
 265         tristate "ACPI Processor P-States driver"
 266         depends on ACPI_PROCESSOR
 267         help
 268         This driver adds a CPUFreq driver which utilizes the ACPI
 269         Processor Performance States.
 270
 271         For details, take a look at <file:Documentation/cpu-freq/>.
 272
 273         If in doubt, say N.
 274 endif
 275
 276 if MIPS
 277 config LOONGSON2_CPUFREQ
 278         tristate "Loongson2 CPUFreq Driver"
 279         help
 280           This option adds a CPUFreq driver for loongson processors which
 281           support software configurable cpu frequency.
 282
 283           Loongson2F and it's successors support this feature.
 284
 285           For details, take a look at <file:Documentation/cpu-freq/>.
 286
 287           If in doubt, say N.
 288
 289 config LOONGSON1_CPUFREQ
 290         tristate "Loongson1 CPUFreq Driver"
 291         help
 292           This option adds a CPUFreq driver for loongson1 processors which
 293           support software configurable cpu frequency.
 294
 295           For details, take a look at <file:Documentation/cpu-freq/>.
 296
 297           If in doubt, say N.
 298 endif
 299
 300 if SPARC64
 301 config SPARC_US3_CPUFREQ
 302         tristate "UltraSPARC-III CPU Frequency driver"
 303         help
 304           This adds the CPUFreq driver for UltraSPARC-III processors.
 305
 306           For details, take a look at <file:Documentation/cpu-freq>.
 307
 308           If in doubt, say N.
 309
 310 config SPARC_US2E_CPUFREQ
 311         tristate "UltraSPARC-IIe CPU Frequency driver"
 312         help
 313           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 314
 315           For details, take a look at <file:Documentation/cpu-freq>.
 316
 317           If in doubt, say N.
 318 endif
 319
 320 if SUPERH
 321 config SH_CPU_FREQ
 322         tristate "SuperH CPU Frequency driver"
 323         help
 324           This adds the cpufreq driver for SuperH. Any CPU that supports
 325           clock rate rounding through the clock framework can use this
 326           driver. While it will make the kernel slightly larger, this is
 327           harmless for CPUs that don't support rate rounding. The driver
 328           will also generate a notice in the boot log before disabling
 329           itself if the CPU in question is not capable of rate rounding.
 330
 331           For details, take a look at <file:Documentation/cpu-freq>.
 332
 333           If unsure, say N.
 334 endif
 335
 336 config QORIQ_CPUFREQ
 337         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 338         depends on OF && COMMON_CLK && (PPC_E500MC || ARM)
 339         depends on !CPU_THERMAL || THERMAL
 340         select CLK_QORIQ
 341         help
 342           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 343           which are capable of changing the CPU's frequency dynamically.
 344
 345 endif
 346 endmenu