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 choice
  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
  48 config 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
  56 config 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
  64 config 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
  73 config 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
  85 config 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
  97 config 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
 107 endchoice
 108
 109 config 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
 120 config 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
 131 config 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
 146 config 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
 164 config 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
 188 config 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
 205 comment "CPU frequency scaling drivers"
 206
 207 config 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
 221 config 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
 230 if X86
 231 source "drivers/cpufreq/Kconfig.x86"
 232 endif
 233
 234 if ARM || ARM64
 235 source "drivers/cpufreq/Kconfig.arm"
 236 endif
 237
 238 if PPC32 || PPC64
 239 source "drivers/cpufreq/Kconfig.powerpc"
 240 endif
 241
 242 if AVR32
 243 config 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.
 250 endif
 251
 252 if IA64
 253 config 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.
 263 endif
 264
 265 if MIPS
 266 config 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
 276 config LOONGSON2_CPUFREQ
 277         tristate "Loongson2 CPUFreq Driver"
 278         depends on LEMOTE_MACH2F
 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         depends on LOONGSON1_LS1B
 292         help
 293           This option adds a CPUFreq driver for loongson1 processors which
 294           support software configurable cpu frequency.
 295
 296           For details, take a look at <file:Documentation/cpu-freq/>.
 297
 298           If in doubt, say N.
 299 endif
 300
 301 if SPARC64
 302 config SPARC_US3_CPUFREQ
 303         tristate "UltraSPARC-III CPU Frequency driver"
 304         help
 305           This adds the CPUFreq driver for UltraSPARC-III processors.
 306
 307           For details, take a look at <file:Documentation/cpu-freq>.
 308
 309           If in doubt, say N.
 310
 311 config SPARC_US2E_CPUFREQ
 312         tristate "UltraSPARC-IIe CPU Frequency driver"
 313         help
 314           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 315
 316           For details, take a look at <file:Documentation/cpu-freq>.
 317
 318           If in doubt, say N.
 319 endif
 320
 321 if SUPERH
 322 config SH_CPU_FREQ
 323         tristate "SuperH CPU Frequency driver"
 324         help
 325           This adds the cpufreq driver for SuperH. Any CPU that supports
 326           clock rate rounding through the clock framework can use this
 327           driver. While it will make the kernel slightly larger, this is
 328           harmless for CPUs that don't support rate rounding. The driver
 329           will also generate a notice in the boot log before disabling
 330           itself if the CPU in question is not capable of rate rounding.
 331
 332           For details, take a look at <file:Documentation/cpu-freq>.
 333
 334           If unsure, say N.
 335 endif
 336
 337 config QORIQ_CPUFREQ
 338         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 339         depends on OF && COMMON_CLK && (PPC_E500MC || ARM || ARM64)
 340         depends on !CPU_THERMAL || THERMAL
 341         select CLK_QORIQ
 342         help
 343           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 344           which are capable of changing the CPU's frequency dynamically.
 345
 346 endif
 347 endmenu