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authorNishanth Menon <nm@ti.com>2012-10-29 15:01:48 -0500
committerMyungJoo Ham <myungjoo.ham@samsung.com>2012-11-20 18:46:24 +0900
commit50a5b33e0159f8783ef617cdb9d5fbb6a3955b6f (patch)
tree0063869677d9da4bc78e4b32de852767e4cd15f0
parent0359d1afe4013d1a216908b6be4c6695a1db6fd6 (diff)
PM / devfreq: Add sysfs node to expose available governors
Now that governor list can be variable, knowing the available governors is useful to be able to select a governor using relevant sysfs node. Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Kevin Hilman <khilman@ti.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
-rw-r--r--Documentation/ABI/testing/sysfs-class-devfreq7
-rw-r--r--drivers/devfreq/devfreq.c22
2 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq
index 66876debca18..0ba6ea2f89d9 100644
--- a/Documentation/ABI/testing/sysfs-class-devfreq
+++ b/Documentation/ABI/testing/sysfs-class-devfreq
@@ -71,3 +71,10 @@ Description:
the available frequencies of the corresponding devfreq object.
This is a snapshot of available frequencies and not limited
by the min/max frequency restrictions.
+
+What: /sys/class/devfreq/.../available_governors
+Date: October 2012
+Contact: Nishanth Menon <nm@ti.com>
+Description:
+ The /sys/class/devfreq/.../available_governors shows
+ currently available governors in the system.
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index ff960f084c11..45e053e5b139 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -730,6 +730,27 @@ out:
ret = count;
return ret;
}
+static ssize_t show_available_governors(struct device *d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct devfreq_governor *tmp_governor;
+ ssize_t count = 0;
+
+ mutex_lock(&devfreq_list_lock);
+ list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
+ count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+ "%s ", tmp_governor->name);
+ mutex_unlock(&devfreq_list_lock);
+
+ /* Truncate the trailing space */
+ if (count)
+ count--;
+
+ count += sprintf(&buf[count], "\n");
+
+ return count;
+}
static ssize_t show_freq(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -917,6 +938,7 @@ static ssize_t show_trans_table(struct device *dev, struct device_attribute *att
static struct device_attribute devfreq_attrs[] = {
__ATTR(governor, S_IRUGO | S_IWUSR, show_governor, store_governor),
+ __ATTR(available_governors, S_IRUGO, show_available_governors, NULL),
__ATTR(cur_freq, S_IRUGO, show_freq, NULL),
__ATTR(available_frequencies, S_IRUGO, show_available_freqs, NULL),
__ATTR(target_freq, S_IRUGO, show_target_freq, NULL),