From 14a34396819960865ff737c665c6e46b64d0e04a Mon Sep 17 00:00:00 2001
From: Kamil Konieczny <k.konieczny@samsung.com>
Date: Thu, 5 Dec 2019 15:55:26 +0100
Subject: PM / devfreq: Add clearing transitions stats

Add clearing transition table and time in states devfreq statistics
by writing 0 (zero) to trans_stat file in devfreq sysfs. An example use
is like following:

echo 0 > /sys/class/devfreq/devfreqX/trans_stat

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
[cw00.choi: Edit return value if entering the wrong value for reset
 and use arrary3_size() to get the size of 3-dimensional array]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

(limited to 'drivers/devfreq/devfreq.c')

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 554d155106a5..af5bd521a734 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1597,7 +1597,34 @@ static ssize_t trans_stat_show(struct device *dev,
 					devfreq->total_trans);
 	return len;
 }
-static DEVICE_ATTR_RO(trans_stat);
+
+static ssize_t trans_stat_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	int err, value;
+
+	if (df->profile->max_state == 0)
+		return count;
+
+	err = kstrtoint(buf, 10, &value);
+	if (err || value != 0)
+		return -EINVAL;
+
+	mutex_lock(&df->lock);
+	memset(df->time_in_state, 0, (df->profile->max_state *
+					sizeof(*df->time_in_state)));
+	memset(df->trans_table, 0, array3_size(sizeof(unsigned int),
+					df->profile->max_state,
+					df->profile->max_state));
+	df->total_trans = 0;
+	df->last_stat_updated = get_jiffies_64();
+	mutex_unlock(&df->lock);
+
+	return count;
+}
+static DEVICE_ATTR_RW(trans_stat);
 
 static struct attribute *devfreq_attrs[] = {
 	&dev_attr_name.attr,
-- 
cgit v1.2.3