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         depends on SMP
 114         select CPU_FREQ_GOV_SCHEDUTIL
 115         select CPU_FREQ_GOV_PERFORMANCE
 116         help
 117           Use the 'schedutil' CPUFreq governor by default. If unsure,
 118           have a look at the help section of that governor. The fallback
 119           governor will be 'performance'.
 120
 121 endchoice
 122
 123 config CPU_FREQ_GOV_PERFORMANCE
 124         tristate "'performance' governor"
 125         help
 126           This cpufreq governor sets the frequency statically to the
 127           highest available CPU frequency.
 128
 129           To compile this driver as a module, choose M here: the
 130           module will be called cpufreq_performance.
 131
 132           If in doubt, say Y.
 133
 134 config CPU_FREQ_GOV_POWERSAVE
 135         tristate "'powersave' governor"
 136         help
 137           This cpufreq governor sets the frequency statically to the
 138           lowest available CPU frequency.
 139
 140           To compile this driver as a module, choose M here: the
 141           module will be called cpufreq_powersave.
 142
 143           If in doubt, say Y.
 144
 145 config CPU_FREQ_GOV_USERSPACE
 146         tristate "'userspace' governor for userspace frequency scaling"
 147         help
 148           Enable this cpufreq governor when you either want to set the
 149           CPU frequency manually or when a userspace program shall
 150           be able to set the CPU dynamically, like on LART
 151           <http://www.lartmaker.nl/>.
 152
 153           To compile this driver as a module, choose M here: the
 154           module will be called cpufreq_userspace.
 155
 156           For details, take a look at <file:Documentation/cpu-freq/>.
 157
 158           If in doubt, say Y.
 159
 160 config CPU_FREQ_GOV_ONDEMAND
 161         tristate "'ondemand' cpufreq policy governor"
 162         select CPU_FREQ_GOV_COMMON
 163         help
 164           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 165           The governor does a periodic polling and
 166           changes frequency based on the CPU utilization.
 167           The support for this governor depends on CPU capability to
 168           do fast frequency switching (i.e, very low latency frequency
 169           transitions).
 170
 171           To compile this driver as a module, choose M here: the
 172           module will be called cpufreq_ondemand.
 173
 174           For details, take a look at linux/Documentation/cpu-freq.
 175
 176           If in doubt, say N.
 177
 178 config CPU_FREQ_GOV_CONSERVATIVE
 179         tristate "'conservative' cpufreq governor"
 180         depends on CPU_FREQ
 181         select CPU_FREQ_GOV_COMMON
 182         help
 183           'conservative' - this driver is rather similar to the 'ondemand'
 184           governor both in its source code and its purpose, the difference is
 185           its optimisation for better suitability in a battery powered
 186           environment.  The frequency is gracefully increased and decreased
 187           rather than jumping to 100% when speed is required.
 188
 189           If you have a desktop machine then you should really be considering
 190           the 'ondemand' governor instead, however if you are using a laptop,
 191           PDA or even an AMD64 based computer (due to the unacceptable
 192           step-by-step latency issues between the minimum and maximum frequency
 193           transitions in the CPU) you will probably want to use this governor.
 194
 195           To compile this driver as a module, choose M here: the
 196           module will be called cpufreq_conservative.
 197
 198           For details, take a look at linux/Documentation/cpu-freq.
 199
 200           If in doubt, say N.
 201
 202 config CPU_FREQ_GOV_SCHEDUTIL
 203         tristate "'schedutil' cpufreq policy governor"
 204         depends on CPU_FREQ && SMP
 205         select CPU_FREQ_GOV_ATTR_SET
 206         select IRQ_WORK
 207         help
 208           This governor makes decisions based on the utilization data provided
 209           by the scheduler.  It sets the CPU frequency to be proportional to
 210           the utilization/capacity ratio coming from the scheduler.  If the
 211           utilization is frequency-invariant, the new frequency is also
 212           proportional to the maximum available frequency.  If that is not the
 213           case, it is proportional to the current frequency of the CPU.  The
 214           frequency tipping point is at utilization/capacity equal to 80% in
 215           both cases.
 216
 217           To compile this driver as a module, choose M here: the module will
 218           be called cpufreq_schedutil.
 219
 220           If in doubt, say N.
 221
 222 comment "CPU frequency scaling drivers"
 223
 224 config CPUFREQ_DT
 225         tristate "Generic DT based cpufreq driver"
 226         depends on HAVE_CLK && OF
 227         # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 228         depends on !CPU_THERMAL || THERMAL
 229         select CPUFREQ_DT_PLATDEV
 230         select PM_OPP
 231         help
 232           This adds a generic DT based cpufreq driver for frequency management.
 233           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 234           systems which share clock and voltage across all CPUs.
 235
 236           If in doubt, say N.
 237
 238 config CPUFREQ_DT_PLATDEV
 239         bool
 240         help
 241           This adds a generic DT based cpufreq platdev driver for frequency
 242           management.  This creates a 'cpufreq-dt' platform device, on the
 243           supported platforms.
 244
 245           If in doubt, say N.
 246
 247 if X86
 248 source "drivers/cpufreq/Kconfig.x86"
 249 endif
 250
 251 if ARM || ARM64
 252 source "drivers/cpufreq/Kconfig.arm"
 253 endif
 254
 255 if PPC32 || PPC64
 256 source "drivers/cpufreq/Kconfig.powerpc"
 257 endif
 258
 259 if AVR32
 260 config AVR32_AT32AP_CPUFREQ
 261         bool "CPU frequency driver for AT32AP"
 262         depends on PLATFORM_AT32AP
 263         default n
 264         help
 265           This enables the CPU frequency driver for AT32AP processors.
 266           If in doubt, say N.
 267 endif
 268
 269 if IA64
 270 config IA64_ACPI_CPUFREQ
 271         tristate "ACPI Processor P-States driver"
 272         depends on ACPI_PROCESSOR
 273         help
 274         This driver adds a CPUFreq driver which utilizes the ACPI
 275         Processor Performance States.
 276
 277         For details, take a look at <file:Documentation/cpu-freq/>.
 278
 279         If in doubt, say N.
 280 endif
 281
 282 if MIPS
 283 config LOONGSON2_CPUFREQ
 284         tristate "Loongson2 CPUFreq Driver"
 285         help
 286           This option adds a CPUFreq driver for loongson processors which
 287           support software configurable cpu frequency.
 288
 289           Loongson2F and it's successors support this feature.
 290
 291           For details, take a look at <file:Documentation/cpu-freq/>.
 292
 293           If in doubt, say N.
 294
 295 config LOONGSON1_CPUFREQ
 296         tristate "Loongson1 CPUFreq Driver"
 297         help
 298           This option adds a CPUFreq driver for loongson1 processors which
 299           support software configurable cpu frequency.
 300
 301           For details, take a look at <file:Documentation/cpu-freq/>.
 302
 303           If in doubt, say N.
 304 endif
 305
 306 if SPARC64
 307 config SPARC_US3_CPUFREQ
 308         tristate "UltraSPARC-III CPU Frequency driver"
 309         help
 310           This adds the CPUFreq driver for UltraSPARC-III processors.
 311
 312           For details, take a look at <file:Documentation/cpu-freq>.
 313
 314           If in doubt, say N.
 315
 316 config SPARC_US2E_CPUFREQ
 317         tristate "UltraSPARC-IIe CPU Frequency driver"
 318         help
 319           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 320
 321           For details, take a look at <file:Documentation/cpu-freq>.
 322
 323           If in doubt, say N.
 324 endif
 325
 326 if SUPERH
 327 config SH_CPU_FREQ
 328         tristate "SuperH CPU Frequency driver"
 329         help
 330           This adds the cpufreq driver for SuperH. Any CPU that supports
 331           clock rate rounding through the clock framework can use this
 332           driver. While it will make the kernel slightly larger, this is
 333           harmless for CPUs that don't support rate rounding. The driver
 334           will also generate a notice in the boot log before disabling
 335           itself if the CPU in question is not capable of rate rounding.
 336
 337           For details, take a look at <file:Documentation/cpu-freq>.
 338
 339           If unsure, say N.
 340 endif
 341
 342 config QORIQ_CPUFREQ
 343         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 344         depends on OF && COMMON_CLK && (PPC_E500MC || ARM)
 345         depends on !CPU_THERMAL || THERMAL
 346         select CLK_QORIQ
 347         help
 348           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 349           which are capable of changing the CPU's frequency dynamically.
 350
 351 endif
 352 endmenu