1 files changed, 70 insertions, 4 deletions

diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 14d768bfa267..6aa46a90ff02 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");