tools/power turbostat: Print cpuidle information

Print cpuidle driver and governor.

Originally-by: Antti Laakso <antti.laakso@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 77f8937..05dbe23 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -3503,6 +3503,23 @@
 	dump_nhm_cst_cfg();
 }
 
+static void dump_sysfs_file(char *path)
+{
+	FILE *input;
+	char cpuidle_buf[64];
+
+	input = fopen(path, "r");
+	if (input == NULL) {
+		if (debug)
+			fprintf(outf, "NSFOD %s\n", path);
+		return;
+	}
+	if (!fgets(cpuidle_buf, sizeof(cpuidle_buf), input))
+		err(1, "%s: failed to read file", path);
+	fclose(input);
+
+	fprintf(outf, "%s: %s", strrchr(path, '/') + 1, cpuidle_buf);
+}
 static void
 dump_sysfs_cstate_config(void)
 {
@@ -3516,6 +3533,15 @@
 	if (!DO_BIC(BIC_sysfs))
 		return;
 
+	if (access("/sys/devices/system/cpu/cpuidle", R_OK)) {
+		fprintf(outf, "cpuidle not loaded\n");
+		return;
+	}
+
+	dump_sysfs_file("/sys/devices/system/cpu/cpuidle/current_driver");
+	dump_sysfs_file("/sys/devices/system/cpu/cpuidle/current_governor");
+	dump_sysfs_file("/sys/devices/system/cpu/cpuidle/current_governor_ro");
+
 	for (state = 0; state < 10; ++state) {
 
 		sprintf(path, "/sys/devices/system/cpu/cpu%d/cpuidle/state%d/name",