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Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
-rw-r--r--drivers/watchdog/watchdog_core.c74
1 files changed, 70 insertions, 4 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 14d768bfa26..6aa46a90ff0 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -34,8 +34,13 @@
#include <linux/kernel.h> /* For printk/panic/... */
#include <linux/watchdog.h> /* For watchdog specific items */
#include <linux/init.h> /* For __init/__exit/... */
+#include <linux/idr.h> /* For ida_* macros */
+#include <linux/err.h> /* For IS_ERR macros */
-#include "watchdog_dev.h" /* For watchdog_dev_register/... */
+#include "watchdog_core.h" /* For watchdog_dev_register/... */
+
+static DEFINE_IDA(watchdog_ida);
+static struct class *watchdog_class;
/**
* watchdog_register_device() - register a watchdog device
@@ -49,7 +54,7 @@
*/
int watchdog_register_device(struct watchdog_device *wdd)
{
- int ret;
+ int ret, id, devno;
if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
return -EINVAL;
@@ -74,10 +79,38 @@ int watchdog_register_device(struct watchdog_device *wdd)
* corrupted in a later stage then we expect a kernel panic!
*/
- /* We only support 1 watchdog device via the /dev/watchdog interface */
+ mutex_init(&wdd->lock);
+ id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
+ if (id < 0)
+ return id;
+ wdd->id = id;
+
ret = watchdog_dev_register(wdd);
if (ret) {
- pr_err("error registering /dev/watchdog (err=%d)\n", ret);
+ ida_simple_remove(&watchdog_ida, id);
+ if (!(id == 0 && ret == -EBUSY))
+ return ret;
+
+ /* Retry in case a legacy watchdog module exists */
+ id = ida_simple_get(&watchdog_ida, 1, MAX_DOGS, GFP_KERNEL);
+ if (id < 0)
+ return id;
+ wdd->id = id;
+
+ ret = watchdog_dev_register(wdd);
+ if (ret) {
+ ida_simple_remove(&watchdog_ida, id);
+ return ret;
+ }
+ }
+
+ devno = wdd->cdev.dev;
+ wdd->dev = device_create(watchdog_class, wdd->parent, devno,
+ NULL, "watchdog%d", wdd->id);
+ if (IS_ERR(wdd->dev)) {
+ watchdog_dev_unregister(wdd);
+ ida_simple_remove(&watchdog_ida, id);
+ ret = PTR_ERR(wdd->dev);
return ret;
}
@@ -95,6 +128,7 @@ EXPORT_SYMBOL_GPL(watchdog_register_device);
void watchdog_unregister_device(struct watchdog_device *wdd)
{
int ret;
+ int devno = wdd->cdev.dev;
if (wdd == NULL)
return;
@@ -102,9 +136,41 @@ void watchdog_unregister_device(struct watchdog_device *wdd)
ret = watchdog_dev_unregister(wdd);
if (ret)
pr_err("error unregistering /dev/watchdog (err=%d)\n", ret);
+ device_destroy(watchdog_class, devno);
+ ida_simple_remove(&watchdog_ida, wdd->id);
+ wdd->dev = NULL;
}
EXPORT_SYMBOL_GPL(watchdog_unregister_device);
+static int __init watchdog_init(void)
+{
+ int err;
+
+ watchdog_class = class_create(THIS_MODULE, "watchdog");
+ if (IS_ERR(watchdog_class)) {
+ pr_err("couldn't create class\n");
+ return PTR_ERR(watchdog_class);
+ }
+
+ err = watchdog_dev_init();
+ if (err < 0) {
+ class_destroy(watchdog_class);
+ return err;
+ }
+
+ return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+ watchdog_dev_exit();
+ class_destroy(watchdog_class);
+ ida_destroy(&watchdog_ida);
+}
+
+subsys_initcall(watchdog_init);
+module_exit(watchdog_exit);
+
MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
MODULE_DESCRIPTION("WatchDog Timer Driver Core");