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_COMMON
  22         bool
  23
  24 config CPU_FREQ_BOOST_SW
  25         bool
  26         depends on THERMAL
  27
  28 config CPU_FREQ_STAT
  29         tristate "CPU frequency translation statistics"
  30         default y
  31         help
  32           This driver exports CPU frequency statistics information through sysfs
  33           file system.
  34
  35           To compile this driver as a module, choose M here: the
  36           module will be called cpufreq_stats.
  37
  38           If in doubt, say N.
  39
  40 config CPU_FREQ_STAT_DETAILS
  41         bool "CPU frequency translation statistics details"
  42         depends on CPU_FREQ_STAT
  43         help
  44           This will show detail CPU frequency translation table in sysfs file
  45           system.
  46
  47           If in doubt, say N.
  48
  49 choice
  50         prompt "Default CPUFreq governor"
  51         default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
  52         default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  53         help
  54           This option sets which CPUFreq governor shall be loaded at
  55           startup. If in doubt, select 'performance'.
  56
  57 config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  58         bool "performance"
  59         select CPU_FREQ_GOV_PERFORMANCE
  60         help
  61           Use the CPUFreq governor 'performance' as default. This sets
  62           the frequency statically to the highest frequency supported by
  63           the CPU.
  64
  65 config CPU_FREQ_DEFAULT_GOV_POWERSAVE
  66         bool "powersave"
  67         select CPU_FREQ_GOV_POWERSAVE
  68         help
  69           Use the CPUFreq governor 'powersave' as default. This sets
  70           the frequency statically to the lowest frequency supported by
  71           the CPU.
  72
  73 config CPU_FREQ_DEFAULT_GOV_USERSPACE
  74         bool "userspace"
  75         select CPU_FREQ_GOV_USERSPACE
  76         help
  77           Use the CPUFreq governor 'userspace' as default. This allows
  78           you to set the CPU frequency manually or when a userspace
  79           program shall be able to set the CPU dynamically without having
  80           to enable the userspace governor manually.
  81
  82 config CPU_FREQ_DEFAULT_GOV_ONDEMAND
  83         bool "ondemand"
  84         select CPU_FREQ_GOV_ONDEMAND
  85         select CPU_FREQ_GOV_PERFORMANCE
  86         help
  87           Use the CPUFreq governor 'ondemand' as default. This allows
  88           you to get a full dynamic frequency capable system by simply
  89           loading your cpufreq low-level hardware driver.
  90           Be aware that not all cpufreq drivers support the ondemand
  91           governor. If unsure have a look at the help section of the
  92           driver. Fallback governor will be the performance governor.
  93
  94 config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
  95         bool "conservative"
  96         select CPU_FREQ_GOV_CONSERVATIVE
  97         select CPU_FREQ_GOV_PERFORMANCE
  98         help
  99           Use the CPUFreq governor 'conservative' as default. This allows
 100           you to get a full dynamic frequency capable system by simply
 101           loading your cpufreq low-level hardware driver.
 102           Be aware that not all cpufreq drivers support the conservative
 103           governor. If unsure have a look at the help section of the
 104           driver. Fallback governor will be the performance governor.
 105 endchoice
 106
 107 config CPU_FREQ_GOV_PERFORMANCE
 108         tristate "'performance' governor"
 109         help
 110           This cpufreq governor sets the frequency statically to the
 111           highest available CPU frequency.
 112
 113           To compile this driver as a module, choose M here: the
 114           module will be called cpufreq_performance.
 115
 116           If in doubt, say Y.
 117
 118 config CPU_FREQ_GOV_POWERSAVE
 119         tristate "'powersave' governor"
 120         help
 121           This cpufreq governor sets the frequency statically to the
 122           lowest available CPU frequency.
 123
 124           To compile this driver as a module, choose M here: the
 125           module will be called cpufreq_powersave.
 126
 127           If in doubt, say Y.
 128
 129 config CPU_FREQ_GOV_USERSPACE
 130         tristate "'userspace' governor for userspace frequency scaling"
 131         help
 132           Enable this cpufreq governor when you either want to set the
 133           CPU frequency manually or when a userspace program shall
 134           be able to set the CPU dynamically, like on LART
 135           <http://www.lartmaker.nl/>.
 136
 137           To compile this driver as a module, choose M here: the
 138           module will be called cpufreq_userspace.
 139
 140           For details, take a look at <file:Documentation/cpu-freq/>.
 141
 142           If in doubt, say Y.
 143
 144 config CPU_FREQ_GOV_ONDEMAND
 145         tristate "'ondemand' cpufreq policy governor"
 146         select CPU_FREQ_GOV_COMMON
 147         help
 148           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 149           The governor does a periodic polling and
 150           changes frequency based on the CPU utilization.
 151           The support for this governor depends on CPU capability to
 152           do fast frequency switching (i.e, very low latency frequency
 153           transitions).
 154
 155           To compile this driver as a module, choose M here: the
 156           module will be called cpufreq_ondemand.
 157
 158           For details, take a look at linux/Documentation/cpu-freq.
 159
 160           If in doubt, say N.
 161
 162 config CPU_FREQ_GOV_CONSERVATIVE
 163         tristate "'conservative' cpufreq governor"
 164         depends on CPU_FREQ
 165         select CPU_FREQ_GOV_COMMON
 166         help
 167           'conservative' - this driver is rather similar to the 'ondemand'
 168           governor both in its source code and its purpose, the difference is
 169           its optimisation for better suitability in a battery powered
 170           environment.  The frequency is gracefully increased and decreased
 171           rather than jumping to 100% when speed is required.
 172
 173           If you have a desktop machine then you should really be considering
 174           the 'ondemand' governor instead, however if you are using a laptop,
 175           PDA or even an AMD64 based computer (due to the unacceptable
 176           step-by-step latency issues between the minimum and maximum frequency
 177           transitions in the CPU) you will probably want to use this governor.
 178
 179           To compile this driver as a module, choose M here: the
 180           module will be called cpufreq_conservative.
 181
 182           For details, take a look at linux/Documentation/cpu-freq.
 183
 184           If in doubt, say N.
 185
 186 comment "CPU frequency scaling drivers"
 187
 188 config CPUFREQ_DT
 189         tristate "Generic DT based cpufreq driver"
 190         depends on HAVE_CLK && OF
 191         # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 192         depends on !CPU_THERMAL || THERMAL
 193         select PM_OPP
 194         help
 195           This adds a generic DT based cpufreq driver for frequency management.
 196           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 197           systems which share clock and voltage across all CPUs.
 198
 199           If in doubt, say N.
 200
 201 if X86
 202 source "drivers/cpufreq/Kconfig.x86"
 203 endif
 204
 205 if ARM || ARM64
 206 source "drivers/cpufreq/Kconfig.arm"
 207 endif
 208
 209 if PPC32 || PPC64
 210 source "drivers/cpufreq/Kconfig.powerpc"
 211 endif
 212
 213 if AVR32
 214 config AVR32_AT32AP_CPUFREQ
 215         bool "CPU frequency driver for AT32AP"
 216         depends on PLATFORM_AT32AP
 217         default n
 218         help
 219           This enables the CPU frequency driver for AT32AP processors.
 220           If in doubt, say N.
 221 endif
 222
 223 if IA64
 224 config IA64_ACPI_CPUFREQ
 225         tristate "ACPI Processor P-States driver"
 226         depends on ACPI_PROCESSOR
 227         help
 228         This driver adds a CPUFreq driver which utilizes the ACPI
 229         Processor Performance States.
 230
 231         For details, take a look at <file:Documentation/cpu-freq/>.
 232
 233         If in doubt, say N.
 234 endif
 235
 236 if MIPS
 237 config LOONGSON2_CPUFREQ
 238         tristate "Loongson2 CPUFreq Driver"
 239         help
 240           This option adds a CPUFreq driver for loongson processors which
 241           support software configurable cpu frequency.
 242
 243           Loongson2F and it's successors support this feature.
 244
 245           For details, take a look at <file:Documentation/cpu-freq/>.
 246
 247           If in doubt, say N.
 248
 249 config LOONGSON1_CPUFREQ
 250         tristate "Loongson1 CPUFreq Driver"
 251         help
 252           This option adds a CPUFreq driver for loongson1 processors which
 253           support software configurable cpu frequency.
 254
 255           For details, take a look at <file:Documentation/cpu-freq/>.
 256
 257           If in doubt, say N.
 258 endif
 259
 260 if SPARC64
 261 config SPARC_US3_CPUFREQ
 262         tristate "UltraSPARC-III CPU Frequency driver"
 263         help
 264           This adds the CPUFreq driver for UltraSPARC-III processors.
 265
 266           For details, take a look at <file:Documentation/cpu-freq>.
 267
 268           If in doubt, say N.
 269
 270 config SPARC_US2E_CPUFREQ
 271         tristate "UltraSPARC-IIe CPU Frequency driver"
 272         help
 273           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 274
 275           For details, take a look at <file:Documentation/cpu-freq>.
 276
 277           If in doubt, say N.
 278 endif
 279
 280 if SUPERH
 281 config SH_CPU_FREQ
 282         tristate "SuperH CPU Frequency driver"
 283         help
 284           This adds the cpufreq driver for SuperH. Any CPU that supports
 285           clock rate rounding through the clock framework can use this
 286           driver. While it will make the kernel slightly larger, this is
 287           harmless for CPUs that don't support rate rounding. The driver
 288           will also generate a notice in the boot log before disabling
 289           itself if the CPU in question is not capable of rate rounding.
 290
 291           For details, take a look at <file:Documentation/cpu-freq>.
 292
 293           If unsure, say N.
 294 endif
 295
 296 endif
 297 endmenu