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         bool "CPU frequency transition statistics"
  35         default y
  36         help
  37           Export CPU frequency statistics information through sysfs.
  38
  39           If in doubt, say N.
  40
  41 config CPU_FREQ_STAT_DETAILS
  42         bool "CPU frequency transition statistics details"
  43         depends on CPU_FREQ_STAT
  44         help
  45           Show detailed CPU frequency transition table in sysfs.
  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
 106 config CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
 107         bool "schedutil"
 108         depends on SMP
 109         select CPU_FREQ_GOV_SCHEDUTIL
 110         select CPU_FREQ_GOV_PERFORMANCE
 111         help
 112           Use the 'schedutil' CPUFreq governor by default. If unsure,
 113           have a look at the help section of that governor. The fallback
 114           governor will be 'performance'.
 115
 116 endchoice
 117
 118 config CPU_FREQ_GOV_PERFORMANCE
 119         tristate "'performance' governor"
 120         help
 121           This cpufreq governor sets the frequency statically to the
 122           highest available CPU frequency.
 123
 124           To compile this driver as a module, choose M here: the
 125           module will be called cpufreq_performance.
 126
 127           If in doubt, say Y.
 128
 129 config CPU_FREQ_GOV_POWERSAVE
 130         tristate "'powersave' governor"
 131         help
 132           This cpufreq governor sets the frequency statically to the
 133           lowest available CPU frequency.
 134
 135           To compile this driver as a module, choose M here: the
 136           module will be called cpufreq_powersave.
 137
 138           If in doubt, say Y.
 139
 140 config CPU_FREQ_GOV_USERSPACE
 141         tristate "'userspace' governor for userspace frequency scaling"
 142         help
 143           Enable this cpufreq governor when you either want to set the
 144           CPU frequency manually or when a userspace program shall
 145           be able to set the CPU dynamically, like on LART
 146           <http://www.lartmaker.nl/>.
 147
 148           To compile this driver as a module, choose M here: the
 149           module will be called cpufreq_userspace.
 150
 151           For details, take a look at <file:Documentation/cpu-freq/>.
 152
 153           If in doubt, say Y.
 154
 155 config CPU_FREQ_GOV_ONDEMAND
 156         tristate "'ondemand' cpufreq policy governor"
 157         select CPU_FREQ_GOV_COMMON
 158         help
 159           'ondemand' - This driver adds a dynamic cpufreq policy governor.
 160           The governor does a periodic polling and
 161           changes frequency based on the CPU utilization.
 162           The support for this governor depends on CPU capability to
 163           do fast frequency switching (i.e, very low latency frequency
 164           transitions).
 165
 166           To compile this driver as a module, choose M here: the
 167           module will be called cpufreq_ondemand.
 168
 169           For details, take a look at linux/Documentation/cpu-freq.
 170
 171           If in doubt, say N.
 172
 173 config CPU_FREQ_GOV_CONSERVATIVE
 174         tristate "'conservative' cpufreq governor"
 175         depends on CPU_FREQ
 176         select CPU_FREQ_GOV_COMMON
 177         help
 178           'conservative' - this driver is rather similar to the 'ondemand'
 179           governor both in its source code and its purpose, the difference is
 180           its optimisation for better suitability in a battery powered
 181           environment.  The frequency is gracefully increased and decreased
 182           rather than jumping to 100% when speed is required.
 183
 184           If you have a desktop machine then you should really be considering
 185           the 'ondemand' governor instead, however if you are using a laptop,
 186           PDA or even an AMD64 based computer (due to the unacceptable
 187           step-by-step latency issues between the minimum and maximum frequency
 188           transitions in the CPU) you will probably want to use this governor.
 189
 190           To compile this driver as a module, choose M here: the
 191           module will be called cpufreq_conservative.
 192
 193           For details, take a look at linux/Documentation/cpu-freq.
 194
 195           If in doubt, say N.
 196
 197 config CPU_FREQ_GOV_SCHEDUTIL
 198         tristate "'schedutil' cpufreq policy governor"
 199         depends on CPU_FREQ && SMP
 200         select CPU_FREQ_GOV_ATTR_SET
 201         select IRQ_WORK
 202         help
 203           This governor makes decisions based on the utilization data provided
 204           by the scheduler.  It sets the CPU frequency to be proportional to
 205           the utilization/capacity ratio coming from the scheduler.  If the
 206           utilization is frequency-invariant, the new frequency is also
 207           proportional to the maximum available frequency.  If that is not the
 208           case, it is proportional to the current frequency of the CPU.  The
 209           frequency tipping point is at utilization/capacity equal to 80% in
 210           both cases.
 211
 212           To compile this driver as a module, choose M here: the module will
 213           be called cpufreq_schedutil.
 214
 215           If in doubt, say N.
 216
 217 comment "CPU frequency scaling drivers"
 218
 219 config CPUFREQ_DT
 220         tristate "Generic DT based cpufreq driver"
 221         depends on HAVE_CLK && OF
 222         # if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 223         depends on !CPU_THERMAL || THERMAL
 224         select CPUFREQ_DT_PLATDEV
 225         select PM_OPP
 226         help
 227           This adds a generic DT based cpufreq driver for frequency management.
 228           It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 229           systems which share clock and voltage across all CPUs.
 230
 231           If in doubt, say N.
 232
 233 config CPUFREQ_DT_PLATDEV
 234         bool
 235         help
 236           This adds a generic DT based cpufreq platdev driver for frequency
 237           management.  This creates a 'cpufreq-dt' platform device, on the
 238           supported platforms.
 239
 240           If in doubt, say N.
 241
 242 if X86
 243 source "drivers/cpufreq/Kconfig.x86"
 244 endif
 245
 246 if ARM || ARM64
 247 source "drivers/cpufreq/Kconfig.arm"
 248 endif
 249
 250 if PPC32 || PPC64
 251 source "drivers/cpufreq/Kconfig.powerpc"
 252 endif
 253
 254 if AVR32
 255 config AVR32_AT32AP_CPUFREQ
 256         bool "CPU frequency driver for AT32AP"
 257         depends on PLATFORM_AT32AP
 258         default n
 259         help
 260           This enables the CPU frequency driver for AT32AP processors.
 261           If in doubt, say N.
 262 endif
 263
 264 if IA64
 265 config IA64_ACPI_CPUFREQ
 266         tristate "ACPI Processor P-States driver"
 267         depends on ACPI_PROCESSOR
 268         help
 269         This driver adds a CPUFreq driver which utilizes the ACPI
 270         Processor Performance States.
 271
 272         For details, take a look at <file:Documentation/cpu-freq/>.
 273
 274         If in doubt, say N.
 275 endif
 276
 277 if MIPS
 278 config LOONGSON2_CPUFREQ
 279         tristate "Loongson2 CPUFreq Driver"
 280         help
 281           This option adds a CPUFreq driver for loongson processors which
 282           support software configurable cpu frequency.
 283
 284           Loongson2F and it's successors support this feature.
 285
 286           For details, take a look at <file:Documentation/cpu-freq/>.
 287
 288           If in doubt, say N.
 289
 290 config LOONGSON1_CPUFREQ
 291         tristate "Loongson1 CPUFreq Driver"
 292         help
 293           This option adds a CPUFreq driver for loongson1 processors which
 294           support software configurable cpu frequency.
 295
 296           For details, take a look at <file:Documentation/cpu-freq/>.
 297
 298           If in doubt, say N.
 299 endif
 300
 301 if SPARC64
 302 config SPARC_US3_CPUFREQ
 303         tristate "UltraSPARC-III CPU Frequency driver"
 304         help
 305           This adds the CPUFreq driver for UltraSPARC-III processors.
 306
 307           For details, take a look at <file:Documentation/cpu-freq>.
 308
 309           If in doubt, say N.
 310
 311 config SPARC_US2E_CPUFREQ
 312         tristate "UltraSPARC-IIe CPU Frequency driver"
 313         help
 314           This adds the CPUFreq driver for UltraSPARC-IIe processors.
 315
 316           For details, take a look at <file:Documentation/cpu-freq>.
 317
 318           If in doubt, say N.
 319 endif
 320
 321 if SUPERH
 322 config SH_CPU_FREQ
 323         tristate "SuperH CPU Frequency driver"
 324         help
 325           This adds the cpufreq driver for SuperH. Any CPU that supports
 326           clock rate rounding through the clock framework can use this
 327           driver. While it will make the kernel slightly larger, this is
 328           harmless for CPUs that don't support rate rounding. The driver
 329           will also generate a notice in the boot log before disabling
 330           itself if the CPU in question is not capable of rate rounding.
 331
 332           For details, take a look at <file:Documentation/cpu-freq>.
 333
 334           If unsure, say N.
 335 endif
 336
 337 config QORIQ_CPUFREQ
 338         tristate "CPU frequency scaling driver for Freescale QorIQ SoCs"
 339         depends on OF && COMMON_CLK && (PPC_E500MC || ARM)
 340         depends on !CPU_THERMAL || THERMAL
 341         select CLK_QORIQ
 342         help
 343           This adds the CPUFreq driver support for Freescale QorIQ SoCs
 344           which are capable of changing the CPU's frequency dynamically.
 345
 346 endif
 347 endmenu