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_TABLE
  21         tristate
  22
  23 config CPU_FREQ_GOV_COMMON
  24         bool
  25
  26 config CPU_FREQ_STAT
  27         tristate "CPU frequency translation statistics"
  28         select CPU_FREQ_TABLE
  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         depends on EXPERT
  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_TABLE
 147         select CPU_FREQ_GOV_COMMON
 148         help
 149           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 150           The governor does a periodic polling and
 151           changes frequency based on the CPU utilization.
 152           The support for this governor depends on CPU capability to
 153           do fast frequency switching (i.e, very low latency frequency
 154           transitions).
 155
 156           To compile this driver as a module, choose M here: the
 157           module will be called cpufreq_ondemand.
 158
 159           For details, take a look at linux/Documentation/cpu-freq.
 160
 161           If in doubt, say N.
 162
 163 config CPU_FREQ_GOV_CONSERVATIVE
 164         tristate "'conservative' cpufreq governor"
 165         depends on CPU_FREQ
 166         select CPU_FREQ_GOV_COMMON
 167         help
 168           'conservative' - this driver is rather similar to the 'ondemand'
 169           governor both in its source code and its purpose, the difference is
 170           its optimisation for better suitability in a battery powered
 171           environment.  The frequency is gracefully increased and decreased
 172           rather than jumping to 100% when speed is required.
 173
 174           If you have a desktop machine then you should really be considering
 175           the 'ondemand' governor instead, however if you are using a laptop,
 176           PDA or even an AMD64 based computer (due to the unacceptable
 177           step-by-step latency issues between the minimum and maximum frequency
 178           transitions in the CPU) you will probably want to use this governor.
 179
 180           To compile this driver as a module, choose M here: the
 181           module will be called cpufreq_conservative.
 182
 183           For details, take a look at linux/Documentation/cpu-freq.
 184
 185           If in doubt, say N.
 186
 187 config GENERIC_CPUFREQ_CPU0
 188         tristate "Generic CPU0 cpufreq driver"
 189         depends on HAVE_CLK && REGULATOR && PM_OPP && OF
 190         select CPU_FREQ_TABLE
 191         help
 192           This adds a generic cpufreq driver for CPU0 frequency management.
 193           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 194           systems which share clock and voltage across all CPUs.
 195
 196           If in doubt, say N.
 197
 198 menu "x86 CPU frequency scaling drivers"
 199 depends on X86
 200 source "drivers/cpufreq/Kconfig.x86"
 201 endmenu
 202
 203 menu "ARM CPU frequency scaling drivers"
 204 depends on ARM
 205 source "drivers/cpufreq/Kconfig.arm"
 206 endmenu
 207
 208 menu "AVR32 CPU frequency scaling drivers"
 209 depends on AVR32
 210
 211 config AVR32_AT32AP_CPUFREQ
 212         bool "CPU frequency driver for AT32AP"
 213         depends on PLATFORM_AT32AP
 214         default n
 215         help
 216           This enables the CPU frequency driver for AT32AP processors.
 217           If in doubt, say N.
 218
 219 endmenu
 220
 221 menu "CPUFreq processor drivers"
 222 depends on IA64
 223
 224 config IA64_ACPI_CPUFREQ
 225         tristate "ACPI Processor P-States driver"
 226         select CPU_FREQ_TABLE
 227         depends on ACPI_PROCESSOR
 228         help
 229         This driver adds a CPUFreq driver which utilizes the ACPI
 230         Processor Performance States.
 231
 232         For details, take a look at <file:Documentation/cpu-freq/>.
 233
 234         If in doubt, say N.
 235
 236 endmenu
 237
 238 menu "MIPS CPUFreq processor drivers"
 239 depends on MIPS
 240
 241 config LOONGSON2_CPUFREQ
 242         tristate "Loongson2 CPUFreq Driver"
 243         select CPU_FREQ_TABLE
 244         help
 245           This option adds a CPUFreq driver for loongson processors which
 246           support software configurable cpu frequency.
 247
 248           Loongson2F and it's successors support this feature.
 249
 250           For details, take a look at <file:Documentation/cpu-freq/>.
 251
 252           If in doubt, say N.
 253
 254 endmenu
 255
 256 menu "PowerPC CPU frequency scaling drivers"
 257 depends on PPC32 || PPC64
 258 source "drivers/cpufreq/Kconfig.powerpc"
 259 endmenu
 260
 261 menu "SPARC CPU frequency scaling drivers"
 262 depends on SPARC64
 263 config SPARC_US3_CPUFREQ
 264         tristate "UltraSPARC-III CPU Frequency driver"
 265         select CPU_FREQ_TABLE
 266         help
 267           This adds the CPUFreq driver for UltraSPARC-III processors.
 268
 269           For details, take a look at <file:Documentation/cpu-freq>.
 270
 271           If in doubt, say N.
 272
 273 config SPARC_US2E_CPUFREQ
 274         tristate "UltraSPARC-IIe CPU Frequency driver"
 275         select CPU_FREQ_TABLE
 276         help
 277           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 278
 279           For details, take a look at <file:Documentation/cpu-freq>.
 280
 281           If in doubt, say N.
 282 endmenu
 283
 284 menu "SH CPU Frequency scaling"
 285 depends on SUPERH
 286 config SH_CPU_FREQ
 287         tristate "SuperH CPU Frequency driver"
 288         select CPU_FREQ_TABLE
 289         help
 290           This adds the cpufreq driver for SuperH. Any CPU that supports
 291           clock rate rounding through the clock framework can use this
 292           driver. While it will make the kernel slightly larger, this is
 293           harmless for CPUs that don't support rate rounding. The driver
 294           will also generate a notice in the boot log before disabling
 295           itself if the CPU in question is not capable of rate rounding.
 296
 297           For details, take a look at <file:Documentation/cpu-freq>.
 298
 299           If unsure, say N.
 300 endmenu
 301
 302 endif
 303 endmenu