[PATCH] watchdog: Add interface to config timeout and pretimeout in sysfs

[Wang Wensheng <wangwensheng4@huawei.com>]

Those interfaces exist already in sysfs of watchdog driver core, but
they are readonly. This patch add write hook so we can config timeout
and pretimeout by writing those files.

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
---
 drivers/watchdog/watchdog_dev.c | 48 +++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 10b2090f3e5e..bb8ddc71d4ea 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -485,7 +485,29 @@ static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
 
 	return sprintf(buf, "%u\n", wdd->timeout);
 }
-static DEVICE_ATTR_RO(timeout);
+
+static ssize_t timeout_store(struct device *dev, struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	int ret;
+	unsigned int val;
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&wd_data->lock);
+	ret = watchdog_set_timeout(wdd, val);
+	mutex_unlock(&wd_data->lock);
+
+	if (!ret)
+		ret = count;
+
+	return ret;
+}
+static DEVICE_ATTR_RW(timeout);
 
 static ssize_t pretimeout_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
@@ -494,7 +516,29 @@ static ssize_t pretimeout_show(struct device *dev,
 
 	return sprintf(buf, "%u\n", wdd->pretimeout);
 }
-static DEVICE_ATTR_RO(pretimeout);
+
+static ssize_t pretimeout_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	int ret;
+	unsigned int val;
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&wd_data->lock);
+	ret = watchdog_set_pretimeout(wdd, val);
+	mutex_unlock(&wd_data->lock);
+
+	if (!ret)
+		ret = count;
+
+	return ret;
+}
+static DEVICE_ATTR_RW(pretimeout);
 
 static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
 				char *buf)
-- 
2.25.0