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authorSascha Hauer <s.hauer@pengutronix.de>2015-08-26 09:48:05 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2015-08-27 21:37:06 +0200
commit8f4cf30903cf6daaed0be1e8911363a3984abf72 (patch)
tree187bf0c5adc9753da483a8100070af98f8c481fc /drivers/watchdog
parent83b0a5ae055bc084938dac96b3ea1c796d99d86c (diff)
downloadbarebox-8f4cf30903cf6daaed0be1e8911363a3984abf72.tar.gz
watchdog: Allow multiple watchdogs
Put watchdogs on a list to allow multiple watchdogs. Add a priority field to be able to pick the highest priority watchdog. This patch also provides a of_get_watchdog_priority() function to allow configuring the watchdog priority from the device tree. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/wd_core.c57
1 files changed, 45 insertions, 12 deletions
diff --git a/drivers/watchdog/wd_core.c b/drivers/watchdog/wd_core.c
index 3d0cfc6..b8473b7 100644
--- a/drivers/watchdog/wd_core.c
+++ b/drivers/watchdog/wd_core.c
@@ -11,6 +11,7 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
+#define pr_fmt(fmt) "watchdog: " fmt
#include <common.h>
#include <command.h>
@@ -18,40 +19,72 @@
#include <linux/ctype.h>
#include <watchdog.h>
-/*
- * Note: this simple framework supports one watchdog only.
- */
-static struct watchdog *watchdog;
+static LIST_HEAD(watchdog_list);
int watchdog_register(struct watchdog *wd)
{
- if (watchdog != NULL)
- return -EBUSY;
+ if (!wd->priority)
+ wd->priority = WATCHDOG_DEFAULT_PRIORITY;
+
+ list_add_tail(&wd->list, &watchdog_list);
+
+ pr_debug("registering watchdog with priority %d\n", wd->priority);
- watchdog = wd;
return 0;
}
EXPORT_SYMBOL(watchdog_register);
int watchdog_deregister(struct watchdog *wd)
{
- if (watchdog == NULL || wd != watchdog)
- return -ENODEV;
+ list_del(&wd->list);
- watchdog = NULL;
return 0;
}
EXPORT_SYMBOL(watchdog_deregister);
+static struct watchdog *watchdog_get_default(void)
+{
+ struct watchdog *tmp, *wd = NULL;
+ int priority = 0;
+
+ list_for_each_entry(tmp, &watchdog_list, list) {
+ if (tmp->priority > priority) {
+ priority = tmp->priority;
+ wd = tmp;
+ }
+ }
+
+ return wd;
+}
+
/*
* start, stop or retrigger the watchdog
* timeout in [seconds]. timeout of '0' will disable the watchdog (if possible)
*/
int watchdog_set_timeout(unsigned timeout)
{
- if (watchdog == NULL)
+ struct watchdog *wd;
+
+ wd = watchdog_get_default();
+
+ if (!wd)
return -ENODEV;
- return watchdog->set_timeout(watchdog, timeout);
+ return wd->set_timeout(wd, timeout);
}
EXPORT_SYMBOL(watchdog_set_timeout);
+
+/**
+ * of_get_watchdog_priority() - get the desired watchdog priority from device tree
+ * @node: The device_node to read the property from
+ *
+ * return: The priority
+ */
+unsigned int of_get_watchdog_priority(struct device_node *node)
+{
+ unsigned int priority = WATCHDOG_DEFAULT_PRIORITY;
+
+ of_property_read_u32(node, "watchdog-priority", &priority);
+
+ return priority;
+}