watchdog: Read device status through sysfs attributes
This patch adds following attributes to watchdog device's sysfs interface
to read its different status.
* state - reads whether device is active or not
* identity - reads Watchdog device's identity string.
* timeout - reads current timeout.
* timeleft - reads timeleft before watchdog generates a reset
* bootstatus - reads status of the watchdog device at boot
* status - reads watchdog device's internal status bits
* nowayout - reads whether nowayout feature was set or not
Testing with iTCO_wdt:
# cd /sys/class/watchdog/watchdog1/
# ls
bootstatus dev device identity nowayout power state
subsystem timeleft timeout uevent
# cat identity
iTCO_wdt
# cat timeout
30
# cat state
inactive
# echo > /dev/watchdog1
# cat timeleft
26
# cat state
active
# cat bootstatus
0
# cat nowayout
0
Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1c427be..71e47dd 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -46,6 +46,13 @@
get killed. If you say Y here, the watchdog cannot be stopped once
it has been started.
+config WATCHDOG_SYSFS
+ bool "Read different watchdog information through sysfs"
+ default n
+ help
+ Say Y here if you want to enable watchdog device status read through
+ sysfs attributes.
+
#
# General Watchdog drivers
#
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 357d23c..551af04 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -249,7 +249,7 @@
devno = wdd->cdev.dev;
wdd->dev = device_create(watchdog_class, wdd->parent, devno,
- NULL, "watchdog%d", wdd->id);
+ wdd, "watchdog%d", wdd->id);
if (IS_ERR(wdd->dev)) {
watchdog_dev_unregister(wdd);
ida_simple_remove(&watchdog_ida, id);
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 055a4e1..f06fbcf 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -247,6 +247,119 @@
return err;
}
+#ifdef CONFIG_WATCHDOG_SYSFS
+static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status));
+}
+static DEVICE_ATTR_RO(nowayout);
+
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ ssize_t status;
+ unsigned int val;
+
+ status = watchdog_get_status(wdd, &val);
+ if (!status)
+ status = sprintf(buf, "%u\n", val);
+
+ return status;
+}
+static DEVICE_ATTR_RO(status);
+
+static ssize_t bootstatus_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", wdd->bootstatus);
+}
+static DEVICE_ATTR_RO(bootstatus);
+
+static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ ssize_t status;
+ unsigned int val;
+
+ status = watchdog_get_timeleft(wdd, &val);
+ if (!status)
+ status = sprintf(buf, "%u\n", val);
+
+ return status;
+}
+static DEVICE_ATTR_RO(timeleft);
+
+static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", wdd->timeout);
+}
+static DEVICE_ATTR_RO(timeout);
+
+static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%s\n", wdd->info->identity);
+}
+static DEVICE_ATTR_RO(identity);
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ if (watchdog_active(wdd))
+ return sprintf(buf, "active\n");
+
+ return sprintf(buf, "inactive\n");
+}
+static DEVICE_ATTR_RO(state);
+
+static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
+ int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ umode_t mode = attr->mode;
+
+ if (attr == &dev_attr_status.attr && !wdd->ops->status)
+ mode = 0;
+ else if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft)
+ mode = 0;
+
+ return mode;
+}
+static struct attribute *wdt_attrs[] = {
+ &dev_attr_state.attr,
+ &dev_attr_identity.attr,
+ &dev_attr_timeout.attr,
+ &dev_attr_timeleft.attr,
+ &dev_attr_bootstatus.attr,
+ &dev_attr_status.attr,
+ &dev_attr_nowayout.attr,
+ NULL,
+};
+
+static const struct attribute_group wdt_group = {
+ .attrs = wdt_attrs,
+ .is_visible = wdt_is_visible,
+};
+__ATTRIBUTE_GROUPS(wdt);
+#else
+#define wdt_groups NULL
+#endif
+
/*
* watchdog_ioctl_op: call the watchdog drivers ioctl op if defined
* @wdd: the watchdog device to do the ioctl on
@@ -584,6 +697,7 @@
static struct class watchdog_class = {
.name = "watchdog",
.owner = THIS_MODULE,
+ .dev_groups = wdt_groups,
};
/*