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_STAT
  30         bool "CPU frequency transition statistics"
  31         help
  32           Export CPU frequency statistics information through sysfs.
  33
  34           If in doubt, say N.
  35
  36 choice
  37         prompt "Default CPUFreq governor"
  38         default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
  39         default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  40         help
  41           This option sets which CPUFreq governor shall be loaded at
  42           startup. If in doubt, select 'performance'.
  43
  44 config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
  45         bool "performance"
  46         select CPU_FREQ_GOV_PERFORMANCE
  47         help
  48           Use the CPUFreq governor 'performance' as default. This sets
  49           the frequency statically to the highest frequency supported by
  50           the CPU.
  51
  52 config CPU_FREQ_DEFAULT_GOV_POWERSAVE
  53         bool "powersave"
  54         select CPU_FREQ_GOV_POWERSAVE
  55         help
  56           Use the CPUFreq governor 'powersave' as default. This sets
  57           the frequency statically to the lowest frequency supported by
  58           the CPU.
  59
  60 config CPU_FREQ_DEFAULT_GOV_USERSPACE
  61         bool "userspace"
  62         select CPU_FREQ_GOV_USERSPACE
  63         help
  64           Use the CPUFreq governor 'userspace' as default. This allows
  65           you to set the CPU frequency manually or when a userspace
  66           program shall be able to set the CPU dynamically without having
  67           to enable the userspace governor manually.
  68
  69 config CPU_FREQ_DEFAULT_GOV_ONDEMAND
  70         bool "ondemand"
  71         select CPU_FREQ_GOV_ONDEMAND
  72         select CPU_FREQ_GOV_PERFORMANCE
  73         help
  74           Use the CPUFreq governor 'ondemand' as default. This allows
  75           you to get a full dynamic frequency capable system by simply
  76           loading your cpufreq low-level hardware driver.
  77           Be aware that not all cpufreq drivers support the ondemand
  78           governor. If unsure have a look at the help section of the
  79           driver. Fallback governor will be the performance governor.
  80
  81 config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
  82         bool "conservative"
  83         select CPU_FREQ_GOV_CONSERVATIVE
  84         select CPU_FREQ_GOV_PERFORMANCE
  85         help
  86           Use the CPUFreq governor 'conservative' 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 conservative
  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_SCHEDUTIL
  94         bool "schedutil"
  95         depends on SMP
  96         select CPU_FREQ_GOV_SCHEDUTIL
  97         select CPU_FREQ_GOV_PERFORMANCE
  98         help
  99           Use the 'schedutil' CPUFreq governor by default. If unsure,
 100           have a look at the help section of that governor. The fallback
 101           governor will be 'performance'.
 102
 103 endchoice
 104
 105 config CPU_FREQ_GOV_PERFORMANCE
 106         tristate "'performance' governor"
 107         help
 108           This cpufreq governor sets the frequency statically to the
 109           highest available CPU frequency.
 110
 111           To compile this driver as a module, choose M here: the
 112           module will be called cpufreq_performance.
 113
 114           If in doubt, say Y.
 115
 116 config CPU_FREQ_GOV_POWERSAVE
 117         tristate "'powersave' governor"
 118         help
 119           This cpufreq governor sets the frequency statically to the
 120           lowest available CPU frequency.
 121
 122           To compile this driver as a module, choose M here: the
 123           module will be called cpufreq_powersave.
 124
 125           If in doubt, say Y.
 126
 127 config CPU_FREQ_GOV_USERSPACE
 128         tristate "'userspace' governor for userspace frequency scaling"
 129         help
 130           Enable this cpufreq governor when you either want to set the
 131           CPU frequency manually or when a userspace program shall
 132           be able to set the CPU dynamically, like on LART
 133           <http://www.lartmaker.nl/>.
 134
 135           To compile this driver as a module, choose M here: the
 136           module will be called cpufreq_userspace.
 137
 138           For details, take a look at <file:Documentation/cpu-freq/>.
 139
 140           If in doubt, say Y.
 141
 142 config CPU_FREQ_GOV_ONDEMAND
 143         tristate "'ondemand' cpufreq policy governor"
 144         select CPU_FREQ_GOV_COMMON
 145         help
 146           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 147           The governor does a periodic polling and
 148           changes frequency based on the CPU utilization.
 149           The support for this governor depends on CPU capability to
 150           do fast frequency switching (i.e, very low latency frequency
 151           transitions).
 152
 153           To compile this driver as a module, choose M here: the
 154           module will be called cpufreq_ondemand.
 155
 156           For details, take a look at linux/Documentation/cpu-freq.
 157
 158           If in doubt, say N.
 159
 160 config CPU_FREQ_GOV_CONSERVATIVE
 161         tristate "'conservative' cpufreq governor"
 162         depends on CPU_FREQ
 163         select CPU_FREQ_GOV_COMMON
 164         help
 165           'conservative' - this driver is rather similar to the 'ondemand'
 166           governor both in its source code and its purpose, the difference is
 167           its optimisation for better suitability in a battery powered
 168           environment.  The frequency is gracefully increased and decreased
 169           rather than jumping to 100% when speed is required.
 170
 171           If you have a desktop machine then you should really be considering
 172           the 'ondemand' governor instead, however if you are using a laptop,
 173           PDA or even an AMD64 based computer (due to the unacceptable
 174           step-by-step latency issues between the minimum and maximum frequency
 175           transitions in the CPU) you will probably want to use this governor.
 176
 177           To compile this driver as a module, choose M here: the
 178           module will be called cpufreq_conservative.
 179
 180           For details, take a look at linux/Documentation/cpu-freq.
 181
 182           If in doubt, say N.
 183
 184 config CPU_FREQ_GOV_SCHEDUTIL
 185         bool "'schedutil' cpufreq policy governor"
 186         depends on CPU_FREQ && SMP
 187         select CPU_FREQ_GOV_ATTR_SET
 188         select IRQ_WORK
 189         help
 190           This governor makes decisions based on the utilization data provided
 191           by the scheduler.  It sets the CPU frequency to be proportional to
 192           the utilization/capacity ratio coming from the scheduler.  If the
 193           utilization is frequency-invariant, the new frequency is also
 194           proportional to the maximum available frequency.  If that is not the
 195           case, it is proportional to the current frequency of the CPU.  The
 196           frequency tipping point is at utilization/capacity equal to 80% in
 197           both cases.
 198
 199           If in doubt, say N.
 200
 201 comment "CPU frequency scaling drivers"
 202
 203 config CPUFREQ_DT
 204         tristate "Generic DT based cpufreq driver"
 205         depends on HAVE_CLK && OF
 206         select CPUFREQ_DT_PLATDEV
 207         select PM_OPP
 208         help
 209           This adds a generic DT based cpufreq driver for frequency management.
 210           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 211           systems.
 212
 213           If in doubt, say N.
 214
 215 config CPUFREQ_DT_PLATDEV
 216         bool
 217         help
 218           This adds a generic DT based cpufreq platdev driver for frequency
 219           management.  This creates a 'cpufreq-dt' platform device, on the
 220           supported platforms.
 221
 222           If in doubt, say N.
 223
 224 if X86
 225 source "drivers/cpufreq/Kconfig.x86"
 226 endif
 227
 228 if ARM || ARM64
 229 source "drivers/cpufreq/Kconfig.arm"
 230 endif
 231
 232 if PPC32 || PPC64
 233 source "drivers/cpufreq/Kconfig.powerpc"
 234 endif
 235
 236 if IA64
 237 config IA64_ACPI_CPUFREQ
 238         tristate "ACPI Processor P-States driver"
 239         depends on ACPI_PROCESSOR
 240         help
 241         This driver adds a CPUFreq driver which utilizes the ACPI
 242         Processor Performance States.
 243
 244         For details, take a look at <file:Documentation/cpu-freq/>.
 245
 246         If in doubt, say N.
 247 endif
 248
 249 if MIPS
 250 config BMIPS_CPUFREQ
 251         tristate "BMIPS CPUfreq Driver"
 252         help
 253           This option adds a CPUfreq driver for BMIPS processors with
 254           support for configurable CPU frequency.
 255
 256           For now, BMIPS5 chips are supported (such as the Broadcom 7425).
 257
 258           If in doubt, say N.
 259
 260 config LOONGSON2_CPUFREQ
 261         tristate "Loongson2 CPUFreq Driver"
 262         depends on LEMOTE_MACH2F
 263         help
 264           This option adds a CPUFreq driver for loongson processors which
 265           support software configurable cpu frequency.
 266
 267           Loongson2F and it's successors support this feature.
 268
 269           For details, take a look at <file:Documentation/cpu-freq/>.
 270
 271           If in doubt, say N.
 272
 273 config LOONGSON1_CPUFREQ
 274         tristate "Loongson1 CPUFreq Driver"
 275         depends on LOONGSON1_LS1B
 276         help
 277           This option adds a CPUFreq driver for loongson1 processors which
 278           support software configurable cpu frequency.
 279
 280           For details, take a look at <file:Documentation/cpu-freq/>.
 281
 282           If in doubt, say N.
 283 endif
 284
 285 if SPARC64
 286 config SPARC_US3_CPUFREQ
 287         tristate "UltraSPARC-III CPU Frequency driver"
 288         help
 289           This adds the CPUFreq driver for UltraSPARC-III processors.
 290
 291           For details, take a look at <file:Documentation/cpu-freq>.
 292
 293           If in doubt, say N.
 294
 295 config SPARC_US2E_CPUFREQ
 296         tristate "UltraSPARC-IIe CPU Frequency driver"
 297         help
 298           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 299
 300           For details, take a look at <file:Documentation/cpu-freq>.
 301
 302           If in doubt, say N.
 303 endif
 304
 305 if SUPERH
 306 config SH_CPU_FREQ
 307         tristate "SuperH CPU Frequency driver"
 308         help
 309           This adds the cpufreq driver for SuperH. Any CPU that supports
 310           clock rate rounding through the clock framework can use this
 311           driver. While it will make the kernel slightly larger, this is
 312           harmless for CPUs that don't support rate rounding. The driver
 313           will also generate a notice in the boot log before disabling
 314           itself if the CPU in question is not capable of rate rounding.
 315
 316           For details, take a look at <file:Documentation/cpu-freq>.
 317
 318           If unsure, say N.
 319 endif
 320
 321 config QORIQ_CPUFREQ
 322         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 323         depends on OF && COMMON_CLK && (PPC_E500MC || ARM || ARM64)
 324         select CLK_QORIQ
 325         help
 326           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 327           which are capable of changing the CPU's frequency dynamically.
 328
 329 endif
 330 endmenu