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/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 25fe430..3c85fc7 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -1,6 +1,6 @@
The Linux WatchDog Timer Driver Core kernel API.
===============================================
-Last reviewed: 16-Mar-2012
+Last reviewed: 21-May-2012
Wim Van Sebroeck <wim@iguana.be>
@@ -39,6 +39,8 @@
The watchdog device structure looks like this:
struct watchdog_device {
+ int id;
+ struct cdev cdev;
const struct watchdog_info *info;
const struct watchdog_ops *ops;
unsigned int bootstatus;
@@ -50,6 +52,12 @@
};
It contains following fields:
+* id: set by watchdog_register_device, id 0 is special. It has both a
+ /dev/watchdog0 cdev (dynamic major, minor 0) as well as the old
+ /dev/watchdog miscdev. The id is set automatically when calling
+ watchdog_register_device.
+* cdev: cdev for the dynamic /dev/watchdog<id> device nodes. This
+ field is also populated by 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.