[PATCH v2] watchdog: Add {min,max}_timeout sysfs nodes

[Juerg Haefliger]

The valid range for the 'timeout' value is useful information so expose
the min and max timeout values via sysfs.

Signed-off-by: Juerg Haefliger <juergh@xxxxxxxxxxxxx>
---

v1->v2:
 - replace sprintf() with sysfs_emit().

 drivers/watchdog/watchdog_dev.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index fe68a97973a5..7c1007ab1b71 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -526,6 +526,24 @@ static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(timeout);
 
+static ssize_t min_timeout_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", wdd->min_timeout);
+}
+static DEVICE_ATTR_RO(min_timeout);
+
+static ssize_t max_timeout_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", wdd->max_timeout);
+}
+static DEVICE_ATTR_RO(max_timeout);
+
 static ssize_t pretimeout_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
@@ -610,6 +628,8 @@ static struct attribute *wdt_attrs[] = {
 	&dev_attr_state.attr,
 	&dev_attr_identity.attr,
 	&dev_attr_timeout.attr,
+	&dev_attr_min_timeout.attr,
+	&dev_attr_max_timeout.attr,
 	&dev_attr_pretimeout.attr,
 	&dev_attr_timeleft.attr,
 	&dev_attr_bootstatus.attr,
-- 
2.27.0