This add the CPUFreq driver support for Intel PXA2xx SOCs.
If in doubt, say N.
+
+config ACPI_CPPC_CPUFREQ
+ tristate "CPUFreq driver based on the ACPI CPPC spec"
+ depends on ACPI
+ select ACPI_CPPC_LIB
+ default n
+ help
+ This adds a CPUFreq driver which uses CPPC methods
+ as described in the ACPIv5.1 spec. CPPC stands for
+ Collaborative Processor Performance Controls. It
+ is based on an abstract continuous scale of CPU
+ performance values which allows the remote power
+ processor to flexibly optimize for power and
+ performance. CPPC relies on power management firmware
+ support for its operation.
+
+ If in doubt, say N.