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 <file:Documentation/cpu-freq/>
15 or 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_POWERNOW_K8
35 tristate "AMD Opteron/Athlon64 PowerNow!"
36 depends on CPU_FREQ_TABLE
38 This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors.
40 For details, take a look at <file:Documentation/cpu-freq/>.
44 config X86_POWERNOW_K8_ACPI
46 depends on ((X86_POWERNOW_K8 = "m" && ACPI_PROCESSOR) || (X86_POWERNOW_K8 = "y" && ACPI_PROCESSOR = "y"))
49 config X86_SPEEDSTEP_CENTRINO
50 tristate "Intel Enhanced SpeedStep"
51 depends on CPU_FREQ_TABLE
53 This adds the CPUFreq driver for Enhanced SpeedStep enabled
54 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
55 or 64bit enabled Intel Xeons.
57 For details, take a look at <file:Documentation/cpu-freq/>.
61 config X86_SPEEDSTEP_CENTRINO_TABLE
63 depends on X86_SPEEDSTEP_CENTRINO
66 config X86_SPEEDSTEP_CENTRINO_ACPI
67 bool "Use ACPI tables to decode valid frequency/voltage pairs (EXPERIMENTAL)"
68 depends on EXPERIMENTAL
69 depends on ((X86_SPEEDSTEP_CENTRINO = "m" && ACPI_PROCESSOR) || (X86_SPEEDSTEP_CENTRINO = "y" && ACPI_PROCESSOR = "y"))
71 Use primarily the information provided in the BIOS ACPI tables
72 to determine valid CPU frequency and voltage pairings.
76 config X86_ACPI_CPUFREQ
77 tristate "ACPI Processor P-States driver"
78 depends on CPU_FREQ_TABLE && ACPI_PROCESSOR
80 This driver adds a CPUFreq driver which utilizes the ACPI
81 Processor Performance States.
83 For details, take a look at <file:Documentation/cpu-freq/>.
87 config X86_ACPI_CPUFREQ_PROC_INTF
88 bool "/proc/acpi/processor/../performance interface (deprecated)"
89 depends on X86_ACPI_CPUFREQ && PROC_FS
91 This enables the deprecated /proc/acpi/processor/../performance
92 interface. While it is helpful for debugging, the generic,
93 cross-architecture cpufreq interfaces should be used.