[PATCH 3/7] devfreq: add clearing transitions stats in sysfs

[Kamil Konieczny]

Add new function trans_reset in sysfs for clearing transition
table and time in states devfreq statistics.

Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>
---
 drivers/devfreq/devfreq.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index ac04b5baef70..0a88055d1362 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1445,6 +1445,31 @@ static ssize_t trans_stat_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(trans_stat);
 
+static void defvreq_stats_clear_table(struct devfreq *devfreq)
+{
+	unsigned int count = devfreq->profile->max_state;
+
+	spin_lock(&devfreq->stats_lock);
+	memset(devfreq->time_in_state, 0, count * sizeof(u64));
+	memset(devfreq->trans_table, 0, count * count * sizeof(int));
+	devfreq->last_stat_updated = get_jiffies_64();
+	devfreq->total_trans = 0;
+	spin_unlock(&devfreq->stats_lock);
+}
+
+static ssize_t trans_reset_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf,
+				 size_t count)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+
+	defvreq_stats_clear_table(devfreq);
+
+	return count;
+}
+static DEVICE_ATTR_WO(trans_reset);
+
 static struct attribute *devfreq_attrs[] = {
 	&dev_attr_governor.attr,
 	&dev_attr_available_governors.attr,
@@ -1455,6 +1480,7 @@ static struct attribute *devfreq_attrs[] = {
 	&dev_attr_min_freq.attr,
 	&dev_attr_max_freq.attr,
 	&dev_attr_trans_stat.attr,
+	&dev_attr_trans_reset.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(devfreq);
-- 
2.24.0