watchdog: create all the proper device files

Create the watchdog class and it's associated devices.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Documentation/watchdog/watchdog-kernel-api.txt

@@ -41,6 +41,8 @@ The watchdog device structure looks like this:
 struct watchdog_device {
 	int id;
 	struct cdev cdev;
+	struct device *dev;
+	struct device *parent;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;
@@ -58,6 +60,9 @@ It contains following fields:
   watchdog_register_device.
 * cdev: cdev for the dynamic /dev/watchdog<id> device nodes. This
   field is also populated by watchdog_register_device.
+* dev: device under the watchdog class (created by watchdog_register_device).
+* parent: set this to the parent device (or NULL) before calling
+  watchdog_register_device.
 * info: a pointer to a watchdog_info structure. This structure gives some
   additional information about the watchdog timer itself. (Like it's unique name)
 * ops: a pointer to the list of watchdog operations that the watchdog supports.

drivers/watchdog/watchdog_core.c

@@ -35,10 +35,12 @@
 #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_core.h"	/* For watchdog_dev_register/... */
 
 static DEFINE_IDA(watchdog_ida);
+static struct class *watchdog_class;
 
 /**
  * watchdog_register_device() - register a watchdog device
@@ -52,7 +54,7 @@ static DEFINE_IDA(watchdog_ida);
  */
 int watchdog_register_device(struct watchdog_device *wdd)
 {
-	int ret, id;
+	int ret, id, devno;
 
 	if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
 		return -EINVAL;
@@ -101,6 +103,16 @@ int watchdog_register_device(struct watchdog_device *wdd)
 		}
 	}
 
+	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;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(watchdog_register_device);
@@ -115,6 +127,7 @@ 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;
@@ -122,18 +135,35 @@ 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)
 {
-	return watchdog_dev_init();
+	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);
 }
 

drivers/watchdog/watchdog_dev.c

@@ -365,6 +365,7 @@ int watchdog_dev_register(struct watchdog_device *watchdog)
 	int err, devno;
 
 	if (watchdog->id == 0) {
+		watchdog_miscdev.parent = watchdog->parent;
 		err = misc_register(&watchdog_miscdev);
 		if (err != 0) {
 			pr_err("%s: cannot register miscdev on minor=%d (err=%d).\n",

include/linux/watchdog.h

@@ -95,6 +95,8 @@ struct watchdog_ops {
  *
  * @id:		The watchdog's ID. (Allocated by watchdog_register_device)
  * @cdev:	The watchdog's Character device.
+ * @dev:	The device for our watchdog
+ * @parent:	The parent bus device
  * @info:	Pointer to a watchdog_info structure.
  * @ops:	Pointer to the list of watchdog operations.
  * @bootstatus:	Status of the watchdog device at boot.
@@ -113,6 +115,8 @@ struct watchdog_ops {
 struct watchdog_device {
 	int id;
 	struct cdev cdev;
+	struct device *dev;
+	struct device *parent;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;