cpufreq: add lagfree governor based on ondemand

Author: tiny4579

drivers/cpufreq/Kconfig

@@ -149,6 +149,18 @@ config CPU_FREQ_DEFAULT_GOV_INTELLIDEMAND
 	help
 	  Intelligent OnDemand Govneror based on Samsung Patched OnDemand
 
+config CPU_FREQ_DEFAULT_GOV_LAGFREE
+	bool "lagfree"
+	select CPU_FREQ_GOV_LAGFREE
+	select CPU_FREQ_GOV_PERFORMANCE
+	help
+	  Use the CPUFreq governor 'lagfree' as default. This allows
+	  you to get a full dynamic frequency capable system by simply
+	  loading your cpufreq low-level hardware driver.
+	  Be aware that not all cpufreq drivers support the lagfree
+	  governor. If unsure have a look at the help section of the
+	  driver. Fallback governor will be the performance governor.
+
 endchoice
 
 config CPU_FREQ_GOV_PERFORMANCE
@@ -271,4 +283,36 @@ config CPU_FREQ_GOV_INTELLIDEMAND
 	help
 	  'intellidemand' - an intelligent ondemand governor
 
+config CPU_FREQ_GOV_LAGFREE
+	tristate "'lagfree' cpufreq governor"
+	depends on CPU_FREQ
+	help
+	  'lagfree' - this driver is rather similar to the 'ondemand'
+	  governor both in its source code and its purpose, the difference is
+	  its optimisation for better suitability in a battery powered
+	  environment.  The frequency is gracefully increased and decreased
+	  rather than jumping to 100% when speed is required.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cpufreq_lagfree.
+
+	  For details, take a look at linux/Documentation/cpu-freq.
+
+	  If in doubt, say N.
+
+config CPU_FREQ_MIN_TICKS
+	int "Ticks between governor polling interval."
+	depends on CPU_FREQ_GOV_LAGFREE
+	default 10
+	help
+	  Minimum number of ticks between polling interval for governors.
+
+config CPU_FREQ_SAMPLING_LATENCY_MULTIPLIER
+	int "Sampling rate multiplier for governors."
+	depends on CPU_FREQ_GOV_LAGFREE
+	default 1000
+	help
+	  Sampling latency rate multiplied by the cpu switch latency.
+	  Affects governor polling.
+
 endif	# CPU_FREQ

drivers/cpufreq/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_SMARTASS)     += cpufreq_smartass.o
 obj-$(CONFIG_CPU_FREQ_GOV_SMARTASS)	+= cpufreq_smartass.o
 obj-$(CONFIG_CPU_FREQ_GOV_SMARTASS2)	+= cpufreq_smartass2.o
 obj-$(CONFIG_CPU_FREQ_GOV_INTELLIDEMAND)+= cpufreq_intellidemand.o
+obj-$(CONFIG_CPU_FREQ_GOV_LAGFREE)      += cpufreq_lagfree.o
 
 # CPUfreq cross-arch helpers
 obj-$(CONFIG_CPU_FREQ_TABLE)		+= freq_table.o