watchdog: Add multiple device support

We keep the old /dev/watchdog interface file for the first watchdog via
miscdev. This is basically a cut and paste of the relevant interface code
from the rtc driver layer tweaked for watchdog.

Revised to fix problems noted by Hans de Goede

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 1984ea6..508d563 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -54,6 +54,8 @@
 #ifdef __KERNEL__
 
 #include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
 
 struct watchdog_ops;
 struct watchdog_device;
@@ -89,6 +91,8 @@
 
 /** struct watchdog_device - The structure that defines a watchdog device
  *
+ * @id:		The watchdog's ID. (Allocated by watchdog_register_device)
+ * @cdev:	The watchdog's Character device.
  * @info:	Pointer to a watchdog_info structure.
  * @ops:	Pointer to the list of watchdog operations.
  * @bootstatus:	Status of the watchdog device at boot.
@@ -105,6 +109,8 @@
  * via the watchdog_set_drvdata and watchdog_get_drvdata helpers.
  */
 struct watchdog_device {
+	int id;
+	struct cdev cdev;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;