[PATCH] watchdog: add nowayout helpers to Watchdog Timer DriverKernel API

From: Wim Van Sebroeck
Date: Tue Nov 29 2011 - 06:18:03 EST


Add two nowayout helpers for the Watchdog Timer Driver Kernel API.

Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx>
---
diff --git a/Documentation/watchdog/00-INDEX b/Documentation/watchdog/00-INDEX
index fc51128..fc9082a 100644
--- a/Documentation/watchdog/00-INDEX
+++ b/Documentation/watchdog/00-INDEX
@@ -1,5 +1,7 @@
00-INDEX
- this file.
+convert_drivers_to_kernel_api.txt
+ - how-to for converting old watchdog drivers to the new kernel API.
hpwdt.txt
- information on the HP iLO2 NMI watchdog
pcwd-watchdog.txt
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 4f7c894..1c443fe 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: 22-Jul-2011
+Last reviewed: 29-Nov-2011

Wim Van Sebroeck <wim@xxxxxxxxx>

@@ -142,6 +142,14 @@ bit-operations. The status bits that are defined are:
* WDOG_NO_WAY_OUT: this bit stores the nowayout setting for the watchdog.
If this bit is set then the watchdog timer will not be able to stop.

+To set the WDOG_NO_WAY_OUT status bit (before registering your watchdog
+timer device) you can either:
+* set it statically in your watchdog_device struct with
+ .status = WATCHDOG_NOWAYOUT_INIT_STATUS,
+ (this will set the value the same as CONFIG_WATCHDOG_NOWAYOUT) or
+* use the following helper function:
+static inline void watchdog_set_nowayout(struct watchdog_device *wdd, int nowayout)
+
Note: The WatchDog Timer Driver Core supports the magic close feature and
the nowayout feature. To use the magic close feature you must set the
WDIOF_MAGICCLOSE bit in the options field of the watchdog's info structure.
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 111843f..43ba5b3 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -53,11 +53,7 @@ struct watchdog_info {

#ifdef __KERNEL__

-#ifdef CONFIG_WATCHDOG_NOWAYOUT
-#define WATCHDOG_NOWAYOUT 1
-#else
-#define WATCHDOG_NOWAYOUT 0
-#endif
+#include <linux/bitops.h>

struct watchdog_ops;
struct watchdog_device;
@@ -122,6 +118,21 @@ struct watchdog_device {
#define WDOG_NO_WAY_OUT 3 /* Is 'nowayout' feature set ? */
};

+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+#define WATCHDOG_NOWAYOUT 1
+#define WATCHDOG_NOWAYOUT_INIT_STATUS (1 << WDOG_NO_WAY_OUT)
+#else
+#define WATCHDOG_NOWAYOUT 0
+#define WATCHDOG_NOWAYOUT_INIT_STATUS 0
+#endif
+
+/* Use the following function to set the nowayout feature */
+static inline void watchdog_set_nowayout(struct watchdog_device *wdd, int nowayout)
+{
+ if (nowayout)
+ set_bit(WDOG_NO_WAY_OUT, &wdd->status);
+}
+
/* Use the following functions to manipulate watchdog driver specific data */
static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
{
--
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