2 # CPU Frequency scaling
5 menu "CPU Frequency scaling"
7 source "drivers/cpufreq/Kconfig"
11 comment "CPUFreq processor drivers"
13 config X86_PCC_CPUFREQ
14 tristate "Processor Clocking Control interface driver"
15 depends on ACPI && ACPI_PROCESSOR
17 This driver adds support for the PCC interface.
19 For details, take a look at:
20 <file:Documentation/cpu-freq/pcc-cpufreq.txt>.
22 To compile this driver as a module, choose M here: the
23 module will be called pcc-cpufreq.
27 config X86_ACPI_CPUFREQ
28 tristate "ACPI Processor P-States driver"
30 depends on ACPI_PROCESSOR
32 This driver adds a CPUFreq driver which utilizes the ACPI
33 Processor Performance States.
34 This driver also supports Intel Enhanced Speedstep.
36 To compile this driver as a module, choose M here: the
37 module will be called acpi-cpufreq.
39 For details, take a look at <file:Documentation/cpu-freq/>.
44 tristate "AMD Elan SC400 and SC410"
48 This adds the CPUFreq driver for AMD Elan SC400 and SC410
51 You need to specify the processor maximum speed as boot
52 parameter: elanfreq=maxspeed (in kHz) or as module
55 For details, take a look at <file:Documentation/cpu-freq/>.
60 tristate "AMD Elan SC520"
64 This adds the CPUFreq driver for AMD Elan SC520 processor.
66 For details, take a look at <file:Documentation/cpu-freq/>.
71 config X86_POWERNOW_K6
72 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
76 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
79 For details, take a look at <file:Documentation/cpu-freq/>.
83 config X86_POWERNOW_K7
84 tristate "AMD Mobile Athlon/Duron PowerNow!"
88 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
90 For details, take a look at <file:Documentation/cpu-freq/>.
94 config X86_POWERNOW_K7_ACPI
96 depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
97 depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
101 config X86_POWERNOW_K8
102 tristate "AMD Opteron/Athlon64 PowerNow!"
103 select CPU_FREQ_TABLE
104 depends on ACPI && ACPI_PROCESSOR
106 This adds the CPUFreq driver for K8/K10 Opteron/Athlon64 processors.
108 To compile this driver as a module, choose M here: the
109 module will be called powernow-k8.
111 For details, take a look at <file:Documentation/cpu-freq/>.
113 config X86_GX_SUSPMOD
114 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
115 depends on X86_32 && PCI
117 This add the CPUFreq driver for NatSemi Geode processors which
118 support suspend modulation.
120 For details, take a look at <file:Documentation/cpu-freq/>.
124 config X86_SPEEDSTEP_CENTRINO
125 tristate "Intel Enhanced SpeedStep (deprecated)"
126 select CPU_FREQ_TABLE
127 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
128 depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
130 This is deprecated and this functionality is now merged into
131 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
133 This adds the CPUFreq driver for Enhanced SpeedStep enabled
134 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
135 or 64bit enabled Intel Xeons.
137 To compile this driver as a module, choose M here: the
138 module will be called speedstep-centrino.
140 For details, take a look at <file:Documentation/cpu-freq/>.
144 config X86_SPEEDSTEP_CENTRINO_TABLE
145 bool "Built-in tables for Banias CPUs"
146 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
149 Use built-in tables for Banias CPUs if ACPI encoding
154 config X86_SPEEDSTEP_ICH
155 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
156 select CPU_FREQ_TABLE
159 This adds the CPUFreq driver for certain mobile Intel Pentium III
160 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
161 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
162 ICH3 or ICH4 southbridge.
164 For details, take a look at <file:Documentation/cpu-freq/>.
168 config X86_SPEEDSTEP_SMI
169 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
170 select CPU_FREQ_TABLE
171 depends on X86_32 && EXPERIMENTAL
173 This adds the CPUFreq driver for certain mobile Intel Pentium III
174 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
175 on systems which have an Intel 440BX/ZX/MX southbridge.
177 For details, take a look at <file:Documentation/cpu-freq/>.
181 config X86_P4_CLOCKMOD
182 tristate "Intel Pentium 4 clock modulation"
183 select CPU_FREQ_TABLE
185 This adds the CPUFreq driver for Intel Pentium 4 / XEON
186 processors. When enabled it will lower CPU temperature by skipping
189 This driver should be only used in exceptional
190 circumstances when very low power is needed because it causes severe
191 slowdowns and noticeable latencies. Normally Speedstep should be used
194 To compile this driver as a module, choose M here: the
195 module will be called p4-clockmod.
197 For details, take a look at <file:Documentation/cpu-freq/>.
199 Unless you are absolutely sure say N.
201 config X86_CPUFREQ_NFORCE2
202 tristate "nVidia nForce2 FSB changing"
203 depends on X86_32 && EXPERIMENTAL
205 This adds the CPUFreq driver for FSB changing on nVidia nForce2
208 For details, take a look at <file:Documentation/cpu-freq/>.
213 tristate "Transmeta LongRun"
216 This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
217 which support LongRun.
219 For details, take a look at <file:Documentation/cpu-freq/>.
224 tristate "VIA Cyrix III Longhaul"
225 select CPU_FREQ_TABLE
226 depends on X86_32 && ACPI_PROCESSOR
228 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
229 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
232 For details, take a look at <file:Documentation/cpu-freq/>.
236 config X86_E_POWERSAVER
237 tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)"
238 select CPU_FREQ_TABLE
239 depends on X86_32 && EXPERIMENTAL
241 This adds the CPUFreq driver for VIA C7 processors. However, this driver
242 does not have any safeguards to prevent operating the CPU out of spec
243 and is thus considered dangerous. Please use the regular ACPI cpufreq
244 driver, enabled by CONFIG_X86_ACPI_CPUFREQ.
248 comment "shared options"
250 config X86_SPEEDSTEP_LIB
252 default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
254 config X86_SPEEDSTEP_RELAXED_CAP_CHECK
255 bool "Relaxed speedstep capability checks"
256 depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
258 Don't perform all checks for a speedstep capable system which would
259 normally be done. Some ancient or strange systems, though speedstep
260 capable, don't always indicate that they are speedstep capable. This
261 option lets the probing code bypass some of those checks if the
262 parameter "relaxed_check=1" is passed to the module.