[IA64] Add ACPI based P-state support
Patch to support P-state transitions on ia64. This driver is based on ACPI,
and uses the ACPI processor driver interface to find out the P-state support
information for the processor. This driver plugs into generic cpufreq
infrastructure.
Once this driver is loaded successfully, ondemand/userspace governor can be
used to change the CPU frequency dynamically based on load or on request from
userspace process.
Refer :
ACPI specification -
http://www.acpi.info
P-state related PAL calls -
http://developer.intel.com/design/itanium/downloads/24869909.pdf
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/cpufreq/Kconfig b/arch/ia64/kernel/cpufreq/Kconfig
new file mode 100644
index 0000000..2d9d527
--- /dev/null
+++ b/arch/ia64/kernel/cpufreq/Kconfig
@@ -0,0 +1,29 @@
+
+#
+# CPU Frequency scaling
+#
+
+menu "CPU Frequency scaling"
+
+source "drivers/cpufreq/Kconfig"
+
+if CPU_FREQ
+
+comment "CPUFreq processor drivers"
+
+config IA64_ACPI_CPUFREQ
+ tristate "ACPI Processor P-States driver"
+ select CPU_FREQ_TABLE
+ depends on ACPI_PROCESSOR
+ help
+ This driver adds a CPUFreq driver which utilizes the ACPI
+ Processor Performance States.
+
+ For details, take a look at <file:Documentation/cpu-freq/>.
+
+ If in doubt, say N.
+
+endif # CPU_FREQ
+
+endmenu
+