drivers/cpufreq/Kconfig

   1 menu "CPU Frequency scaling"
   2
   3 config CPU_FREQ
   4         bool "CPU Frequency scaling"
   5         help
   6           CPU Frequency scaling allows you to change the clock speed of
   7           CPUs on the fly. This is a nice method to save power, because
   8           the lower the CPU clock speed, the less power the CPU consumes.
   9
  10           Note that this driver doesn't automatically change the CPU
  11           clock speed, you need to either enable a dynamic cpufreq governor
  12           (see below) after boot, or use a userspace tool.
  13
  14           For details, take a look at <file:Documentation/cpu-freq>.
  15
  16           If in doubt, say N.
  17
  18 if CPU_FREQ
  19
  20 config CPU_FREQ_GOV_COMMON
  21         bool
  22
  23 config CPU_FREQ_BOOST_SW
  24         bool
  25         depends on THERMAL
  26
  27 config CPU_FREQ_STAT
  28         tristate "CPU frequency translation statistics"
  29         default y
  30         help
  31           This driver exports CPU frequency statistics information through sysfs
  32           file system.
  33
  34           To compile this driver as a module, choose M here: the
  35           module will be called cpufreq_stats.
  36
  37           If in doubt, say N.
  38
  39 config CPU_FREQ_STAT_DETAILS
  40         bool "CPU frequency translation statistics details"
  41         depends on CPU_FREQ_STAT
  42         help
  43           This will show detail CPU frequency translation table in sysfs file
  44           system.
  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 endchoice
 105
 106 config CPU_FREQ_GOV_PERFORMANCE
 107         tristate "'performance' governor"
 108         help
 109           This cpufreq governor sets the frequency statically to the
 110           highest available CPU frequency.
 111
 112           To compile this driver as a module, choose M here: the
 113           module will be called cpufreq_performance.
 114
 115           If in doubt, say Y.
 116
 117 config CPU_FREQ_GOV_POWERSAVE
 118         tristate "'powersave' governor"
 119         help
 120           This cpufreq governor sets the frequency statically to the
 121           lowest available CPU frequency.
 122
 123           To compile this driver as a module, choose M here: the
 124           module will be called cpufreq_powersave.
 125
 126           If in doubt, say Y.
 127
 128 config CPU_FREQ_GOV_USERSPACE
 129         tristate "'userspace' governor for userspace frequency scaling"
 130         help
 131           Enable this cpufreq governor when you either want to set the
 132           CPU frequency manually or when a userspace program shall
 133           be able to set the CPU dynamically, like on LART
 134           <http://www.lartmaker.nl/>.
 135
 136           To compile this driver as a module, choose M here: the
 137           module will be called cpufreq_userspace.
 138
 139           For details, take a look at <file:Documentation/cpu-freq/>.
 140
 141           If in doubt, say Y.
 142
 143 config CPU_FREQ_GOV_ONDEMAND
 144         tristate "'ondemand' cpufreq policy governor"
 145         select CPU_FREQ_GOV_COMMON
 146         help
 147           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 148           The governor does a periodic polling and
 149           changes frequency based on the CPU utilization.
 150           The support for this governor depends on CPU capability to
 151           do fast frequency switching (i.e, very low latency frequency
 152           transitions).
 153
 154           To compile this driver as a module, choose M here: the
 155           module will be called cpufreq_ondemand.
 156
 157           For details, take a look at linux/Documentation/cpu-freq.
 158
 159           If in doubt, say N.
 160
 161 config CPU_FREQ_GOV_CONSERVATIVE
 162         tristate "'conservative' cpufreq governor"
 163         depends on CPU_FREQ
 164         select CPU_FREQ_GOV_COMMON
 165         help
 166           'conservative' - this driver is rather similar to the 'ondemand'
 167           governor both in its source code and its purpose, the difference is
 168           its optimisation for better suitability in a battery powered
 169           environment.  The frequency is gracefully increased and decreased
 170           rather than jumping to 100% when speed is required.
 171
 172           If you have a desktop machine then you should really be considering
 173           the 'ondemand' governor instead, however if you are using a laptop,
 174           PDA or even an AMD64 based computer (due to the unacceptable
 175           step-by-step latency issues between the minimum and maximum frequency
 176           transitions in the CPU) you will probably want to use this governor.
 177
 178           To compile this driver as a module, choose M here: the
 179           module will be called cpufreq_conservative.
 180
 181           For details, take a look at linux/Documentation/cpu-freq.
 182
 183           If in doubt, say N.
 184
 185 comment "CPU frequency scaling drivers"
 186
 187 config CPUFREQ_DT
 188         tristate "Generic DT based cpufreq driver"
 189         depends on HAVE_CLK && OF
 190         # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 191         depends on !CPU_THERMAL || THERMAL
 192         select PM_OPP
 193         help
 194           This adds a generic DT based cpufreq driver for frequency management.
 195           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 196           systems which share clock and voltage across all CPUs.
 197
 198           If in doubt, say N.
 199
 200 if X86
 201 source "drivers/cpufreq/Kconfig.x86"
 202 endif
 203
 204 if ARM || ARM64
 205 source "drivers/cpufreq/Kconfig.arm"
 206 endif
 207
 208 if PPC32 || PPC64
 209 source "drivers/cpufreq/Kconfig.powerpc"
 210 endif
 211
 212 if AVR32
 213 config AVR32_AT32AP_CPUFREQ
 214         bool "CPU frequency driver for AT32AP"
 215         depends on PLATFORM_AT32AP
 216         default n
 217         help
 218           This enables the CPU frequency driver for AT32AP processors.
 219           If in doubt, say N.
 220 endif
 221
 222 if IA64
 223 config IA64_ACPI_CPUFREQ
 224         tristate "ACPI Processor P-States driver"
 225         depends on ACPI_PROCESSOR
 226         help
 227         This driver adds a CPUFreq driver which utilizes the ACPI
 228         Processor Performance States.
 229
 230         For details, take a look at <file:Documentation/cpu-freq/>.
 231
 232         If in doubt, say N.
 233 endif
 234
 235 if MIPS
 236 config LOONGSON2_CPUFREQ
 237         tristate "Loongson2 CPUFreq Driver"
 238         help
 239           This option adds a CPUFreq driver for loongson processors which
 240           support software configurable cpu frequency.
 241
 242           Loongson2F and it's successors support this feature.
 243
 244           For details, take a look at <file:Documentation/cpu-freq/>.
 245
 246           If in doubt, say N.
 247
 248 config LOONGSON1_CPUFREQ
 249         tristate "Loongson1 CPUFreq Driver"
 250         help
 251           This option adds a CPUFreq driver for loongson1 processors which
 252           support software configurable cpu frequency.
 253
 254           For details, take a look at <file:Documentation/cpu-freq/>.
 255
 256           If in doubt, say N.
 257 endif
 258
 259 if SPARC64
 260 config SPARC_US3_CPUFREQ
 261         tristate "UltraSPARC-III CPU Frequency driver"
 262         help
 263           This adds the CPUFreq driver for UltraSPARC-III processors.
 264
 265           For details, take a look at <file:Documentation/cpu-freq>.
 266
 267           If in doubt, say N.
 268
 269 config SPARC_US2E_CPUFREQ
 270         tristate "UltraSPARC-IIe CPU Frequency driver"
 271         help
 272           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 273
 274           For details, take a look at <file:Documentation/cpu-freq>.
 275
 276           If in doubt, say N.
 277 endif
 278
 279 if SUPERH
 280 config SH_CPU_FREQ
 281         tristate "SuperH CPU Frequency driver"
 282         help
 283           This adds the cpufreq driver for SuperH. Any CPU that supports
 284           clock rate rounding through the clock framework can use this
 285           driver. While it will make the kernel slightly larger, this is
 286           harmless for CPUs that don't support rate rounding. The driver
 287           will also generate a notice in the boot log before disabling
 288           itself if the CPU in question is not capable of rate rounding.
 289
 290           For details, take a look at <file:Documentation/cpu-freq>.
 291
 292           If unsure, say N.
 293 endif
 294
 295 endif
 296 endmenu