2 # CPU Frequency scaling
5 menu "CPU Frequency scaling"
8 bool "CPU Frequency scaling"
10 Clock scaling allows you to change the clock speed of CPUs on the
11 fly. This is a nice method to save battery power on notebooks,
12 because the lower the clock speed, the less power the CPU consumes.
14 For more information, take a look at linux/Documentation/cpu-freq or
15 at <http://www.codemonkey.org.uk/projects/cpufreq/>
19 source "drivers/cpufreq/Kconfig"
22 tristate "CPU frequency table helpers"
26 Many CPUFreq drivers use these helpers, so only say N here if
27 the CPUFreq driver of your choice doesn't need these helpers.
31 comment "CPUFreq processor drivers"
34 config X86_ACPI_CPUFREQ
35 tristate "ACPI Processor P-States driver"
36 depends on CPU_FREQ_TABLE && ACPI_PROCESSOR
38 This driver adds a CPUFreq driver which utilizes the ACPI
39 Processor Performance States.
41 For details, take a look at linux/Documentation/cpu-freq.
45 config X86_ACPI_CPUFREQ_PROC_INTF
46 bool "/proc/acpi/processor/../performance interface (deprecated)"
47 depends on X86_ACPI_CPUFREQ && PROC_FS
49 This enables the deprecated /proc/acpi/processor/../performance
50 interface. While it is helpful for debugging, the generic,
51 cross-architecture cpufreq interfaces should be used.
57 depends on CPU_FREQ_TABLE && MELAN
59 This adds the CPUFreq driver for AMD Elan SC400 and SC410
62 You need to specify the processor maximum speed as boot
63 parameter: elanfreq=maxspeed (in kHz) or as module
66 For details, take a look at linux/Documentation/cpu-freq.
70 config X86_POWERNOW_K6
71 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
72 depends on CPU_FREQ_TABLE
74 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
77 For details, take a look at linux/Documentation/cpu-freq.
81 config X86_POWERNOW_K7
82 tristate "AMD Mobile Athlon/Duron PowerNow!"
83 depends on CPU_FREQ_TABLE
85 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
87 For details, take a look at linux/Documentation/cpu-freq.
91 config X86_POWERNOW_K8
92 tristate "AMD Opteron/Athlon64 PowerNow!"
93 depends on CPU_FREQ && EXPERIMENTAL
95 This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors.
97 For details, take a look at linux/Documentation/cpu-freq.
101 config X86_GX_SUSPMOD
102 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
105 This add the CPUFreq driver for NatSemi Geode processors which
106 support suspend modulation.
108 For details, take a look at linux/Documentation/cpu-freq.
112 config X86_SPEEDSTEP_CENTRINO
113 tristate "Intel Enhanced SpeedStep"
114 depends on CPU_FREQ_TABLE
116 This adds the CPUFreq driver for Enhanced SpeedStep enabled
117 mobile CPUs. This means Intel Pentium M (Centrino) CPUs.
119 For details, take a look at linux/Documentation/cpu-freq.
123 config X86_SPEEDSTEP_ICH
124 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
125 depends on CPU_FREQ_TABLE
127 This adds the CPUFreq driver for certain mobile Intel Pentium III
128 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
129 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
130 ICH3 or ICH4 southbridge.
132 For details, take a look at linux/Documentation/cpu-freq.
136 config X86_SPEEDSTEP_SMI
137 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
138 depends on CPU_FREQ_TABLE && EXPERIMENTAL
140 This adds the CPUFreq driver for certain mobile Intel Pentium III
141 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
142 on systems which have an Intel 440BX/ZX/MX southbridge.
144 For details, take a look at linux/Documentation/cpu-freq.
148 config X86_P4_CLOCKMOD
149 tristate "Intel Pentium 4 clock modulation"
150 depends on CPU_FREQ_TABLE
152 This adds the CPUFreq driver for Intel Pentium 4 / XEON
155 For details, take a look at linux/Documentation/cpu-freq.
159 config X86_SPEEDSTEP_LIB
161 depends on (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
162 default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
165 tristate "Transmeta LongRun"
168 This adds the CPUFreq driver for Transmeta Crusoe processors which
171 For details, take a look at linux/Documentation/cpu-freq.
176 tristate "VIA Cyrix III Longhaul"
177 depends on CPU_FREQ_TABLE
179 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
180 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
183 For details, take a look at linux/Documentation/cpu-freq.