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         tristate "CPU frequency translation statistics"
  35         default y
  36         help
  37           This driver exports CPU frequency statistics information through sysfs
  38           file system.
  39
  40           To compile this driver as a module, choose M here: the
  41           module will be called cpufreq_stats.
  42
  43           If in doubt, say N.
  44
  45 config CPU_FREQ_STAT_DETAILS
  46         bool "CPU frequency translation statistics details"
  47         depends on CPU_FREQ_STAT
  48         help
  49           This will show detail CPU frequency translation table in sysfs file
  50           system.
  51
  52           If in doubt, say N.
  53
  54 choice
  55         prompt "Default CPUFreq governor"
  56         default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
  57         default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  58         help
  59           This option sets which CPUFreq governor shall be loaded at
  60           startup. If in doubt, select 'performance'.
  61
  62 config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  63         bool "performance"
  64         select CPU_FREQ_GOV_PERFORMANCE
  65         help
  66           Use the CPUFreq governor 'performance' as default. This sets
  67           the frequency statically to the highest frequency supported by
  68           the CPU.
  69
  70 config CPU_FREQ_DEFAULT_GOV_POWERSAVE
  71         bool "powersave"
  72         select CPU_FREQ_GOV_POWERSAVE
  73         help
  74           Use the CPUFreq governor 'powersave' as default. This sets
  75           the frequency statically to the lowest frequency supported by
  76           the CPU.
  77
  78 config CPU_FREQ_DEFAULT_GOV_USERSPACE
  79         bool "userspace"
  80         select CPU_FREQ_GOV_USERSPACE
  81         help
  82           Use the CPUFreq governor 'userspace' as default. This allows
  83           you to set the CPU frequency manually or when a userspace
  84           program shall be able to set the CPU dynamically without having
  85           to enable the userspace governor manually.
  86
  87 config CPU_FREQ_DEFAULT_GOV_ONDEMAND
  88         bool "ondemand"
  89         select CPU_FREQ_GOV_ONDEMAND
  90         select CPU_FREQ_GOV_PERFORMANCE
  91         help
  92           Use the CPUFreq governor 'ondemand' as default. This allows
  93           you to get a full dynamic frequency capable system by simply
  94           loading your cpufreq low-level hardware driver.
  95           Be aware that not all cpufreq drivers support the ondemand
  96           governor. If unsure have a look at the help section of the
  97           driver. Fallback governor will be the performance governor.
  98
  99 config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
 100         bool "conservative"
 101         select CPU_FREQ_GOV_CONSERVATIVE
 102         select CPU_FREQ_GOV_PERFORMANCE
 103         help
 104           Use the CPUFreq governor 'conservative' as default. This allows
 105           you to get a full dynamic frequency capable system by simply
 106           loading your cpufreq low-level hardware driver.
 107           Be aware that not all cpufreq drivers support the conservative
 108           governor. If unsure have a look at the help section of the
 109           driver. Fallback governor will be the performance governor.
 110
 111 config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
 112         bool "schedutil"
 113         select CPU_FREQ_GOV_SCHEDUTIL
 114         select CPU_FREQ_GOV_PERFORMANCE
 115         help
 116           Use the 'schedutil' CPUFreq governor by default. If unsure,
 117           have a look at the help section of that governor. The fallback
 118           governor will be 'performance'.
 119
 120 endchoice
 121
 122 config CPU_FREQ_GOV_PERFORMANCE
 123         tristate "'performance' governor"
 124         help
 125           This cpufreq governor sets the frequency statically to the
 126           highest available CPU frequency.
 127
 128           To compile this driver as a module, choose M here: the
 129           module will be called cpufreq_performance.
 130
 131           If in doubt, say Y.
 132
 133 config CPU_FREQ_GOV_POWERSAVE
 134         tristate "'powersave' governor"
 135         help
 136           This cpufreq governor sets the frequency statically to the
 137           lowest available CPU frequency.
 138
 139           To compile this driver as a module, choose M here: the
 140           module will be called cpufreq_powersave.
 141
 142           If in doubt, say Y.
 143
 144 config CPU_FREQ_GOV_USERSPACE
 145         tristate "'userspace' governor for userspace frequency scaling"
 146         help
 147           Enable this cpufreq governor when you either want to set the
 148           CPU frequency manually or when a userspace program shall
 149           be able to set the CPU dynamically, like on LART
 150           <http://www.lartmaker.nl/>.
 151
 152           To compile this driver as a module, choose M here: the
 153           module will be called cpufreq_userspace.
 154
 155           For details, take a look at <file:Documentation/cpu-freq/>.
 156
 157           If in doubt, say Y.
 158
 159 config CPU_FREQ_GOV_ONDEMAND
 160         tristate "'ondemand' cpufreq policy governor"
 161         select CPU_FREQ_GOV_COMMON
 162         help
 163           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 164           The governor does a periodic polling and
 165           changes frequency based on the CPU utilization.
 166           The support for this governor depends on CPU capability to
 167           do fast frequency switching (i.e, very low latency frequency
 168           transitions).
 169
 170           To compile this driver as a module, choose M here: the
 171           module will be called cpufreq_ondemand.
 172
 173           For details, take a look at linux/Documentation/cpu-freq.
 174
 175           If in doubt, say N.
 176
 177 config CPU_FREQ_GOV_CONSERVATIVE
 178         tristate "'conservative' cpufreq governor"
 179         depends on CPU_FREQ
 180         select CPU_FREQ_GOV_COMMON
 181         help
 182           'conservative' - this driver is rather similar to the 'ondemand'
 183           governor both in its source code and its purpose, the difference is
 184           its optimisation for better suitability in a battery powered
 185           environment.  The frequency is gracefully increased and decreased
 186           rather than jumping to 100% when speed is required.
 187
 188           If you have a desktop machine then you should really be considering
 189           the 'ondemand' governor instead, however if you are using a laptop,
 190           PDA or even an AMD64 based computer (due to the unacceptable
 191           step-by-step latency issues between the minimum and maximum frequency
 192           transitions in the CPU) you will probably want to use this governor.
 193
 194           To compile this driver as a module, choose M here: the
 195           module will be called cpufreq_conservative.
 196
 197           For details, take a look at linux/Documentation/cpu-freq.
 198
 199           If in doubt, say N.
 200
 201 config CPU_FREQ_GOV_SCHEDUTIL
 202         tristate "'schedutil' cpufreq policy governor"
 203         depends on CPU_FREQ && SMP
 204         select CPU_FREQ_GOV_ATTR_SET
 205         select IRQ_WORK
 206         help
 207           This governor makes decisions based on the utilization data provided
 208           by the scheduler.  It sets the CPU frequency to be proportional to
 209           the utilization/capacity ratio coming from the scheduler.  If the
 210           utilization is frequency-invariant, the new frequency is also
 211           proportional to the maximum available frequency.  If that is not the
 212           case, it is proportional to the current frequency of the CPU.  The
 213           frequency tipping point is at utilization/capacity equal to 80% in
 214           both cases.
 215
 216           To compile this driver as a module, choose M here: the module will
 217           be called cpufreq_schedutil.
 218
 219           If in doubt, say N.
 220
 221 comment "CPU frequency scaling drivers"
 222
 223 config CPUFREQ_DT
 224         tristate "Generic DT based cpufreq driver"
 225         depends on HAVE_CLK && OF
 226         # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 227         depends on !CPU_THERMAL || THERMAL
 228         select PM_OPP
 229         help
 230           This adds a generic DT based cpufreq driver for frequency management.
 231           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 232           systems which share clock and voltage across all CPUs.
 233
 234           If in doubt, say N.
 235
 236 if X86
 237 source "drivers/cpufreq/Kconfig.x86"
 238 endif
 239
 240 if ARM || ARM64
 241 source "drivers/cpufreq/Kconfig.arm"
 242 endif
 243
 244 if PPC32 || PPC64
 245 source "drivers/cpufreq/Kconfig.powerpc"
 246 endif
 247
 248 if AVR32
 249 config AVR32_AT32AP_CPUFREQ
 250         bool "CPU frequency driver for AT32AP"
 251         depends on PLATFORM_AT32AP
 252         default n
 253         help
 254           This enables the CPU frequency driver for AT32AP processors.
 255           If in doubt, say N.
 256 endif
 257
 258 if IA64
 259 config IA64_ACPI_CPUFREQ
 260         tristate "ACPI Processor P-States driver"
 261         depends on ACPI_PROCESSOR
 262         help
 263         This driver adds a CPUFreq driver which utilizes the ACPI
 264         Processor Performance States.
 265
 266         For details, take a look at <file:Documentation/cpu-freq/>.
 267
 268         If in doubt, say N.
 269 endif
 270
 271 if MIPS
 272 config LOONGSON2_CPUFREQ
 273         tristate "Loongson2 CPUFreq Driver"
 274         help
 275           This option adds a CPUFreq driver for loongson processors which
 276           support software configurable cpu frequency.
 277
 278           Loongson2F and it's successors support this feature.
 279
 280           For details, take a look at <file:Documentation/cpu-freq/>.
 281
 282           If in doubt, say N.
 283
 284 config LOONGSON1_CPUFREQ
 285         tristate "Loongson1 CPUFreq Driver"
 286         help
 287           This option adds a CPUFreq driver for loongson1 processors which
 288           support software configurable cpu frequency.
 289
 290           For details, take a look at <file:Documentation/cpu-freq/>.
 291
 292           If in doubt, say N.
 293 endif
 294
 295 if SPARC64
 296 config SPARC_US3_CPUFREQ
 297         tristate "UltraSPARC-III CPU Frequency driver"
 298         help
 299           This adds the CPUFreq driver for UltraSPARC-III processors.
 300
 301           For details, take a look at <file:Documentation/cpu-freq>.
 302
 303           If in doubt, say N.
 304
 305 config SPARC_US2E_CPUFREQ
 306         tristate "UltraSPARC-IIe CPU Frequency driver"
 307         help
 308           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 309
 310           For details, take a look at <file:Documentation/cpu-freq>.
 311
 312           If in doubt, say N.
 313 endif
 314
 315 if SUPERH
 316 config SH_CPU_FREQ
 317         tristate "SuperH CPU Frequency driver"
 318         help
 319           This adds the cpufreq driver for SuperH. Any CPU that supports
 320           clock rate rounding through the clock framework can use this
 321           driver. While it will make the kernel slightly larger, this is
 322           harmless for CPUs that don't support rate rounding. The driver
 323           will also generate a notice in the boot log before disabling
 324           itself if the CPU in question is not capable of rate rounding.
 325
 326           For details, take a look at <file:Documentation/cpu-freq>.
 327
 328           If unsure, say N.
 329 endif
 330
 331 config QORIQ_CPUFREQ
 332         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 333         depends on OF && COMMON_CLK && (PPC_E500MC || ARM)
 334         depends on !CPU_THERMAL || THERMAL
 335         select CLK_QORIQ
 336         help
 337           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 338           which are capable of changing the CPU's frequency dynamically.
 339
 340 endif
 341 endmenu