watchdog: WatchDog Timer Driver Core - Part 5
This part add's the WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl
functionality to the WatchDog Timer Driver Core framework.
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx>
diff -urN linux-2.6.38-generic-part4/Documentation/watchdog/src/watchdog-with-timer-example.c linux-2.6.38-generic-part5/Documentation/watchdog/src/watchdog-with-timer-example.c
--- linux-2.6.38-generic-part4/Documentation/watchdog/src/watchdog-with-timer-example.c 2011-06-16 20:08:16.987178248 +0200
+++ linux-2.6.38-generic-part5/Documentation/watchdog/src/watchdog-with-timer-example.c 2011-06-16 20:13:58.331178125 +0200
@@ -110,12 +110,20 @@
return 0;
}
+static int wdt_set_timeout(struct watchdog_device *wdd, int new_timeout)
+{
+ if (new_timeout < 1)
+ return -EINVAL;
+ return 0;
+}
+
/*
* The watchdog kernel structures
*/
static const struct watchdog_info wdt_info = {
.identity = DRV_NAME,
- .options = WDIOF_KEEPALIVEPING,
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING,
};
static const struct watchdog_ops wdt_ops = {
@@ -123,6 +131,7 @@
.start = wdt_start,
.stop = wdt_stop,
.ping = wdt_ping,
+ .set_timeout = wdt_set_timeout,
};
static struct watchdog_device wdt_dev = {
@@ -140,6 +149,9 @@
/* Register other stuff */
+ /* Set watchdog_device parameters */
+ wdt_dev.timeout = timeout;
+
/* Register the watchdog timer device */
res = watchdog_register_device(&wdt_dev);
if (res) {
diff -urN linux-2.6.38-generic-part4/Documentation/watchdog/watchdog-kernel-api.txt linux-2.6.38-generic-part5/Documentation/watchdog/watchdog-kernel-api.txt
--- linux-2.6.38-generic-part4/Documentation/watchdog/watchdog-kernel-api.txt 2011-06-16 19:14:34.603180137 +0200
+++ linux-2.6.38-generic-part5/Documentation/watchdog/watchdog-kernel-api.txt 2011-06-16 20:09:01.759178229 +0200
@@ -42,6 +42,7 @@
char *name;
const struct watchdog_info *info;
const struct watchdog_ops *ops;
+ int timeout;
int bootstatus;
long status;
};
@@ -51,6 +52,7 @@
* info: a pointer to a watchdog_info structure. This structure gives some
additional information about the watchdog timer itself.
* ops: a pointer to the list of watchdog operations that the watchdog supports.
+* timeout: the watchdog timer's timeout value (in seconds).
* bootstatus: status of the device after booting (reported with watchdog
WDIOF_* status bits).
* status: this field contains a number of status bits that give extra
@@ -68,6 +70,7 @@
/* optional operations */
int (*ping)(struct watchdog_device *);
int (*status)(struct watchdog_device *);
+ int (*set_timeout)(struct watchdog_device *, int);
};
It is important that you first define the module owner of the watchdog timer
@@ -107,6 +110,12 @@
info structure).
* status: this routine checks the status of the watchdog timer device. The
status of the device is reported with watchdog WDIOF_* status flags/bits.
+* set_timeout: this routine checks and changes the timeout of the watchdog
+ timer device. It returns 0 on success and an errno code on failure. On success
+ the timeout value of the watchdog_device will be changed to the value that
+ was just used to re-program the watchdog timer device.
+ (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
+ watchdog's info structure).
The status bits should (preferably) be set with the set_bit and clear_bit alike
bit-operations. The status bit's that are defined are:
diff -urN linux-2.6.38-generic-part4/drivers/watchdog/core/watchdog_dev.c linux-2.6.38-generic-part5/drivers/watchdog/core/watchdog_dev.c
--- linux-2.6.38-generic-part4/drivers/watchdog/core/watchdog_dev.c 2011-06-16 19:36:11.571178880 +0200
+++ linux-2.6.38-generic-part5/drivers/watchdog/core/watchdog_dev.c 2011-06-16 20:09:01.759178229 +0200
@@ -223,6 +223,26 @@
return -EOPNOTSUPP;
watchdog_ping(wdd);
return 0;
+ case WDIOC_SETTIMEOUT:
+ if ((wdd->ops->set_timeout == NULL) ||
+ !(wdd->info->options & WDIOF_SETTIMEOUT))
+ return -EOPNOTSUPP;
+ if (get_user(val, p))
+ return -EFAULT;
+ err = wdd->ops->set_timeout(wdd, val);
+ if (err < 0)
+ return err;
+ wdd->timeout = val;
+ /* If the watchdog is active then we sent a keepalive ping
+ * to make sure that the watchdog keep's running (and if
+ * possible that it takes the new timeout) */
+ watchdog_ping(wdd);
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ /* timeout == 0 means that we don't know the timeout */
+ if (wdd->timeout)
+ return put_user(wdd->timeout, p);
+ return -EOPNOTSUPP;
default:
return -ENOTTY;
}
diff -urN linux-2.6.38-generic-part4/include/linux/watchdog.h linux-2.6.38-generic-part5/include/linux/watchdog.h
--- linux-2.6.38-generic-part4/include/linux/watchdog.h 2011-06-16 19:14:34.603180137 +0200
+++ linux-2.6.38-generic-part5/include/linux/watchdog.h 2011-06-16 20:09:01.759178229 +0200
@@ -71,6 +71,7 @@
/* optional operations */
int (*ping)(struct watchdog_device *);
int (*status)(struct watchdog_device *);
+ int (*set_timeout)(struct watchdog_device *, int);
};
/* The structure that defines a watchdog device */
@@ -79,6 +80,7 @@
const struct watchdog_info *info;
const struct watchdog_ops *ops;
int bootstatus;
+ int timeout;
long status;
#define WDOG_ACTIVE 0 /* is the watchdog running/active */
#define WDOG_DEV_OPEN 1 /* is the watchdog opened via
--
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