diff --git a/src/Makefile.am b/src/Makefile.am
index 6886388..fee1ffa 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -32,7 +32,7 @@ powertop_SOURCES = parameters/persistent.cpp parameters/learn.cpp parameters/par
 		report/report-formatter-csv.cpp report/report-formatter-csv.h \
 		report/report-formatter-html.cpp report/report-formatter-html.h \
 		report/report-data-html.cpp report/report-data-html.h \
-		main.cpp css.h powertop.css cpu/intel_gpu.cpp \
+		main.cpp css.h powertop.css cpu/intel_gpu.cpp devices/devfreq.cpp \
 		cpu/rapl/rapl_interface.cpp cpu/cpu_rapl_device.cpp cpu/rapl/rapl_interface.h\
 		cpu/dram_rapl_device.cpp devices/gpu_rapl_device.cpp cpu/cpu_rapl_device.h \
 		cpu/dram_rapl_device.h devices/gpu_rapl_device.h
diff --git a/src/devices/devfreq.cpp b/src/devices/devfreq.cpp
new file mode 100644
index 0000000..29d7790
--- /dev/null
+++ b/src/devices/devfreq.cpp
@@ -0,0 +1,351 @@
+/*
+ * Copyright 2012, Linaro
+ *
+ * This file is part of PowerTOP
+ *
+ * This program file is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program in a file named COPYING; if not, write to the
+ * Free Software Foundation, Inc,
+ * 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ * or just google for it.
+ *
+ * Authors:
+ *	Rajagopal Venkat <rajagopal.venkat@linaro.org>
+ */
+
+#include <iostream>
+#include <fstream>
+
+#include <dirent.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "device.h"
+#include "devfreq.h"
+#include "../display.h"
+#include "../cpu/cpu.h"
+#include "../report/report.h"
+#include "../report/report-maker.h"
+
+static bool is_enabled = true;
+
+static vector<class devfreq *> all_devfreq;
+
+devfreq::devfreq(const char* dpath): device()
+{
+	strncpy(dir_name, dpath, sizeof(dir_name));
+}
+
+uint64_t devfreq::parse_freq_time(char* pchr)
+{
+	char *cptr, *pptr = pchr;
+	uint64_t ctime;
+
+	cptr = strtok(pchr, " :");
+	while (cptr != NULL) {
+		cptr = strtok(NULL, " :");
+		if (cptr )
+			pptr = cptr;
+	}
+
+	ctime = strtoull(pptr, NULL, 10);
+	return ctime;
+}
+
+void devfreq::process_time_stamps()
+{
+	unsigned int i;
+	uint64_t active_time = 0;
+
+	sample_time = (1000000.0 * (stamp_after.tv_sec - stamp_before.tv_sec))
+			+ ((stamp_after.tv_usec - stamp_before.tv_usec) );
+
+	for (i=0; i < dstates.size()-1; i++) {
+		struct frequency *state = dstates[i];
+		state->time_after = 1000 * (state->time_after - state->time_before);
+		active_time += state->time_after;
+	}
+	/* Compute idle time for the device */
+	dstates[i]->time_after = sample_time - active_time;
+}
+
+void devfreq::add_devfreq_freq_state(uint64_t freq, uint64_t time)
+{
+	struct frequency *state;
+
+	state = new(std::nothrow) struct frequency;
+	if (!state)
+		return;
+
+	memset(state, 0, sizeof(*state));
+	dstates.push_back(state);
+
+	state->freq = freq;
+	if (freq == 0)
+		strcpy(state->human_name, "Idle");
+	else
+		hz_to_human(freq, state->human_name);
+	state->time_before = time;
+}
+
+void devfreq::update_devfreq_freq_state(uint64_t freq, uint64_t time)
+{
+	unsigned int i;
+	struct frequency *state = NULL;
+
+	for(i=0; i < dstates.size(); i++) {
+		if (freq == dstates[i]->freq)
+			state = dstates[i];
+	}
+
+	if (state == NULL) {
+		add_devfreq_freq_state(freq, time);
+		return;
+	}
+
+	state->time_after = time;
+}
+
+void devfreq::parse_devfreq_trans_stat(char *dname)
+{
+	ifstream file;
+	char filename[256];
+
+	sprintf(filename, "/sys/class/devfreq/%s/trans_stat", dir_name);
+	file.open(filename);
+
+	if (!file)
+		return;
+
+	char line[1024];
+	char *c;
+
+	while (file) {
+		uint64_t freq;
+		uint64_t time;
+		char *pchr;
+
+		memset(line, 0, sizeof(line));
+		file.getline(line, sizeof(line));
+
+		pchr = strchr(line, '*');
+		pchr = (pchr != NULL) ? pchr+1 : line;
+
+		freq = strtoull(pchr, &c, 10);
+		if (!freq)
+			continue;
+
+		time = parse_freq_time(pchr);
+		update_devfreq_freq_state(freq, time);
+	}
+	file.close();
+}
+
+void devfreq::start_measurement(void)
+{
+	unsigned int i;
+	ifstream file;
+
+	for (i=0; i < dstates.size(); i++)
+		delete dstates[i];
+	dstates.resize(0);
+	sample_time = 0;
+
+	gettimeofday(&stamp_before, NULL);
+	parse_devfreq_trans_stat(dir_name);
+	/* add device idle state */
+	update_devfreq_freq_state(0, 0);
+}
+
+void devfreq::end_measurement(void)
+{
+	parse_devfreq_trans_stat(dir_name);
+	gettimeofday(&stamp_after, NULL);
+	process_time_stamps();
+}
+
+double devfreq::power_usage(struct result_bundle *result, struct parameter_bundle *bundle)
+{
+	return 0;
+}
+
+double devfreq::utilization(void)
+{
+	return 0;
+}
+
+void devfreq::fill_freq_utilization(unsigned int idx, char *buf)
+{
+	buf[0] = 0;
+
+	if (idx < dstates.size() && dstates[idx]) {
+		struct frequency *state = dstates[idx];
+		sprintf(buf, " %5.1f%% ", percentage(1.0 * state->time_after / sample_time));
+	}
+}
+
+void devfreq::fill_freq_name(unsigned int idx, char *buf)
+{
+	buf[0] = 0;
+
+	if (idx < dstates.size() && dstates[idx]) {
+		sprintf(buf, "%-15s", dstates[idx]->human_name);
+	}
+}
+
+void start_devfreq_measurement(void)
+{
+	unsigned int i;
+
+	for (i=0; i<all_devfreq.size(); i++)
+		all_devfreq[i]->start_measurement();
+}
+
+void end_devfreq_measurement(void)
+{
+	unsigned int i;
+
+	for (i=0; i<all_devfreq.size(); i++)
+		all_devfreq[i]->end_measurement();
+}
+
+static void devfreq_dev_callback(const char *d_name)
+{
+	devfreq *df = new(std::nothrow) class devfreq(d_name);
+	if (df)
+		all_devfreq.push_back(df);
+}
+
+void create_all_devfreq_devices(void)
+{
+	DIR *dir;
+	std::string p = "/sys/class/devfreq/";
+	dir = opendir(p.c_str());
+	if (dir == NULL) {
+		fprintf(stderr, "Devfreq not enabled\n");
+		is_enabled = false;
+		return;
+	}
+
+	callback fn = &devfreq_dev_callback;
+	process_directory(p.c_str(), fn);
+}
+
+void initialize_devfreq(void)
+{
+	if (is_enabled)
+		create_tab("Device Freq stats", _("Device Freq stats"));
+}
+
+void display_devfreq_devices(void)
+{
+	unsigned int i, j;
+	WINDOW *win;
+	char fline[1024];
+	char buf[128];
+
+	win = get_ncurses_win("Device Freq stats");
+        if (!win)
+                return;
+
+        wclear(win);
+        wmove(win, 2,0);
+
+	if (!is_enabled) {
+		wprintw(win, _(" Devfreq is not enabled"));
+		return;
+	}
+
+	if (!all_devfreq.size()) {
+		wprintw(win, _(" No devfreq devices available"));
+		return;
+	}
+
+	for (i=0; i<all_devfreq.size(); i++) {
+
+		class devfreq *df = all_devfreq[i];
+		wprintw(win, "\n%s\n", df->device_name());
+
+		for(j=0; j < df->dstates.size(); j++) {
+			memset(fline, 0, sizeof(fline));
+			strcpy(fline, "\t");
+			df->fill_freq_name(j, buf);
+			strcat(fline, buf);
+			df->fill_freq_utilization(j, buf);
+			strcat(fline, buf);
+			strcat(fline, "\n");
+			wprintw(win, fline);
+		}
+		wprintw(win, "\n");
+	}
+}
+
+void report_devfreq_devices(void)
+{
+	if (!is_enabled) {
+		return;
+	}
+
+/* todo: adapt to new report format */
+#if 0
+	char buffer[512];
+	unsigned int i, j;
+
+	report.begin_section(SECTION_DEVFREQ);
+	report.add_header("Device Frequency Report");
+
+	report.begin_table(TABLE_WIDE);
+	if (!all_devfreq.size()) {
+		report.begin_row();
+		report.add(" No devfreq devices available");
+		return;
+	}
+
+	for (i = 0; i < all_devfreq.size(); i++) {
+		buffer[0] = 0;
+		class devfreq *df = all_devfreq[i];
+
+		report.begin_row();
+		report.begin_cell(CELL_CPU_PSTATE_HEADER);
+		report.addf("%s", df->device_name());
+
+		for (j = 0; j < df->dstates.size(); j++) {
+			report.begin_row();
+			report.begin_cell(CELL_CPU_STATE_VALUE);
+			df->fill_freq_name(j, buffer);
+			report.add(buffer);
+			report.begin_cell(CELL_CPU_STATE_VALUE);
+			df->fill_freq_utilization(j, buffer);
+			report.add(buffer);
+		}
+	}
+#endif
+
+}
+
+void clear_all_devfreq()
+{
+	unsigned int i, j;
+
+	for (i=0; i < all_devfreq.size(); i++) {
+		class devfreq *df = all_devfreq[i];
+
+		for(j=0; j < df->dstates.size(); j++)
+			delete df->dstates[j];
+
+		df->dstates.resize(0);
+		delete df;
+	}
+	all_devfreq.clear();
+}
diff --git a/src/devices/devfreq.h b/src/devices/devfreq.h
new file mode 100644
index 0000000..8ab5705
--- /dev/null
+++ b/src/devices/devfreq.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2012, Linaro
+ *
+ * This file is part of PowerTOP
+ *
+ * This program file is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program in a file named COPYING; if not, write to the
+ * Free Software Foundation, Inc,
+ * 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ * or just google for it.
+ *
+ * Authors:
+ *	Rajagopal Venkat <rajagopal.venkat@linaro.org>
+ */
+#ifndef _INCLUDE_GUARD_DEVFREQ_H
+#define _INCLUDE_GUARD_DEVFREQ_H
+
+#include "device.h"
+#include "../parameters/parameters.h"
+
+struct frequency;
+
+class devfreq: public device {
+	char dir_name[4096];
+	struct timeval  stamp_before, stamp_after;
+	double sample_time;
+
+	uint64_t parse_freq_time(char *ptr);
+	void add_devfreq_freq_state(uint64_t freq, uint64_t time);
+	void update_devfreq_freq_state(uint64_t freq, uint64_t time);
+	void parse_devfreq_trans_stat(char *dname);
+	void process_time_stamps();
+
+public:
+
+	vector<struct frequency *> dstates;
+
+	devfreq(const char *c);
+	void fill_freq_utilization(unsigned int idx, char *buf);
+	void fill_freq_name(unsigned int idx, char *buf);
+
+	virtual void start_measurement(void);
+	virtual void end_measurement(void);
+
+	virtual double	utilization(void); /* percentage */
+
+	virtual const char * class_name(void) { return "devfreq";};
+
+	virtual const char * device_name(void) { return dir_name;};
+	virtual const char * human_name(void) { return "devfreq";};
+	virtual double power_usage(struct result_bundle *result, struct parameter_bundle *bundle);
+	virtual const char * util_units(void) { return " rpm"; };
+	virtual int power_valid(void) { return 0; /*utilization_power_valid(r_index);*/};
+	virtual int grouping_prio(void) { return 1; };
+};
+
+extern void create_all_devfreq_devices(void);
+extern void clear_all_devfreq(void);
+extern void display_devfreq_devices(void);
+extern void report_devfreq_devices(void);
+extern void initialize_devfreq(void);
+extern void start_devfreq_measurement(void);
+extern void end_devfreq_measurement(void);
+
+#endif
diff --git a/src/main.cpp b/src/main.cpp
index cf4e547..d33eaed 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -48,6 +48,7 @@
 
 
 #include "devices/device.h"
+#include "devices/devfreq.h"
 #include "devices/usb.h"
 #include "devices/ahci.h"
 #include "measurement/measurement.h"
@@ -194,6 +195,7 @@ void one_measurement(int seconds, char *workload)
 	create_all_usb_devices();
 	start_power_measurement();
 	devices_start_measurement();
+	start_devfreq_measurement();
 	start_process_measurement();
 	start_cpu_measurement();
 
@@ -206,6 +208,7 @@ void one_measurement(int seconds, char *workload)
 	end_cpu_measurement();
 	end_process_measurement();
 	collect_open_devices();
+	end_devfreq_measurement();
 	devices_end_measurement();
 	end_power_measurement();
 
@@ -233,6 +236,9 @@ void one_measurement(int seconds, char *workload)
 	report_show_open_devices();
 
 	report_devices();
+	display_devfreq_devices();
+	report_devfreq_devices();
+
 	ahci_create_device_stats_table();
 	store_results(measurement_time);
 	end_cpu_data();
@@ -344,6 +350,7 @@ static void powertop_init(void)
 
 	enumerate_cpus();
 	create_all_devices();
+	create_all_devfreq_devices();
 	detect_power_meters();
 
 	register_parameter("base power", 100, 0.5);
@@ -457,6 +464,7 @@ int main(int argc, char **argv)
 		exit(0);
 	}
 	init_display();
+	initialize_devfreq();
 	initialize_tuning();
 	/* first one is short to not let the user wait too long */
 	one_measurement(1, NULL);
@@ -491,6 +499,7 @@ int main(int argc, char **argv)
 
 	clean_open_devices();
 	clear_all_devices();
+	clear_all_devfreq();
 	clear_all_cpus();
 
 	return 0;
diff --git a/src/report/report-maker.h b/src/report/report-maker.h
index 423568a..bda4cef 100644
--- a/src/report/report-maker.h
+++ b/src/report/report-maker.h
@@ -89,6 +89,7 @@ enum section_type {
 	SECTION_SYSINFO,
 	SECTION_CPUIDLE,
 	SECTION_CPUFREQ,
+	SECTION_DEVFREQ,
 	SECTION_DEVPOWER,
 	SECTION_SOFTWARE,
 	SECTION_SUMMARY,
