[PATCH 2/10 v2] Generic Watchdog Timer Driver
From: Wim Van Sebroeck
Date: Sat Jun 18 2011 - 13:20:51 EST
watchdog: WatchDog Timer Driver Core - Part 2
This part add's the basic ioctl functionality to the
WatchDog Timer Driver Core framework. The supported
ioctl call's are:
WDIOC_GETSUPPORT
WDIOC_GETSTATUS
WDIOC_GETBOOTSTATUS
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx>
diff -urN linux-2.6.38-generic-part1/Documentation/watchdog/src/watchdog-with-timer-example.c linux-2.6.38-generic-part2/Documentation/watchdog/src/watchdog-with-timer-example.c
--- linux-2.6.38-generic-part1/Documentation/watchdog/src/watchdog-with-timer-example.c 2011-06-16 20:07:33.939170516 +0200
+++ linux-2.6.38-generic-part2/Documentation/watchdog/src/watchdog-with-timer-example.c 2011-06-16 20:07:44.671177621 +0200
@@ -115,6 +115,10 @@
/*
* The watchdog kernel structures
*/
+static const struct watchdog_info wdt_info = {
+ .identity = DRV_NAME,
+};
+
static const struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
@@ -124,6 +128,7 @@
static struct watchdog_device wdt_dev = {
.name = DRV_NAME,
+ .info = &wdt_info,
.ops = &wdt_ops,
};
diff -urN linux-2.6.38-generic-part1/Documentation/watchdog/watchdog-kernel-api.txt linux-2.6.38-generic-part2/Documentation/watchdog/watchdog-kernel-api.txt
--- linux-2.6.38-generic-part1/Documentation/watchdog/watchdog-kernel-api.txt 2011-06-16 14:26:05.928061789 +0200
+++ linux-2.6.38-generic-part2/Documentation/watchdog/watchdog-kernel-api.txt 2011-06-16 16:57:31.388541823 +0200
@@ -40,13 +40,19 @@
struct watchdog_device {
char *name;
+ const struct watchdog_info *info;
const struct watchdog_ops *ops;
+ int bootstatus;
long status;
};
It contains following fields:
* name: a pointer to the (preferably unique) name of the watchdog timer device.
+* 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.
+* 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
information about the status of the device (Like: is the device opened via
the /dev/watchdog interface or not, ...)
@@ -60,6 +66,7 @@
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
+ int (*status)(struct watchdog_device *);
};
It is important that you first define the module owner of the watchdog timer
@@ -94,6 +101,8 @@
the watchdog timer driver core does: to send a keepalive ping to the watchdog
timer hardware it will either use the ping operation (when available) or the
start operation (when the ping operation is not available).
+* status: this routine checks the status of the watchdog timer device. The
+ status of the device is reported with watchdog WDIOF_* status flags/bits.
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-part1/drivers/watchdog/core/watchdog_core.c linux-2.6.38-generic-part2/drivers/watchdog/core/watchdog_core.c
--- linux-2.6.38-generic-part1/drivers/watchdog/core/watchdog_core.c 2011-06-16 19:24:39.955179826 +0200
+++ linux-2.6.38-generic-part2/drivers/watchdog/core/watchdog_core.c 2011-06-16 19:33:08.647178048 +0200
@@ -59,7 +59,7 @@
int ret;
/* Make sure we have a valid watchdog_device structure */
- if (wdd == NULL || wdd->ops == NULL)
+ if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
return -ENODATA;
/* Make sure that the mandatory operations are supported */
diff -urN linux-2.6.38-generic-part1/drivers/watchdog/core/watchdog_dev.c linux-2.6.38-generic-part2/drivers/watchdog/core/watchdog_dev.c
--- linux-2.6.38-generic-part1/drivers/watchdog/core/watchdog_dev.c 2011-06-16 19:32:27.183186141 +0200
+++ linux-2.6.38-generic-part2/drivers/watchdog/core/watchdog_dev.c 2011-06-16 19:34:22.927178838 +0200
@@ -125,6 +125,41 @@
}
/*
+ * watchdog_ioctl: handle the different ioctl's for the watchdog device.
+ * @file: file handle to the device
+ * @cmd: watchdog command
+ * @arg: argument pointer
+ *
+ * The watchdog API defines a common set of functions for all watchdogs
+ * according to their available features.
+ */
+
+static long watchdog_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ int val = 0;
+
+ trace("%p, %u, %li", file, cmd, arg);
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, wdd->info,
+ sizeof(struct watchdog_info)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ if (wdd->ops->status)
+ val = wdd->ops->status(wdd);
+ return put_user(val, p);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(wdd->bootstatus, p);
+ default:
+ return -ENOTTY;
+ }
+ return -ENOTTY;
+}
+
+/*
* watchdog_open: open the /dev/watchdog device.
* @inode: inode of device
* @file: file handle to device
@@ -202,6 +237,7 @@
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = watchdog_write,
+ .unlocked_ioctl = watchdog_ioctl,
.open = watchdog_open,
.release = watchdog_release,
};
diff -urN linux-2.6.38-generic-part1/include/linux/watchdog.h linux-2.6.38-generic-part2/include/linux/watchdog.h
--- linux-2.6.38-generic-part1/include/linux/watchdog.h 2011-06-16 14:28:32.848061741 +0200
+++ linux-2.6.38-generic-part2/include/linux/watchdog.h 2011-06-16 16:57:31.388541823 +0200
@@ -70,12 +70,15 @@
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
+ int (*status)(struct watchdog_device *);
};
/* The structure that defines a watchdog device */
struct watchdog_device {
char *name;
+ const struct watchdog_info *info;
const struct watchdog_ops *ops;
+ int bootstatus;
long status;
#define WDOG_DEV_OPEN 1 /* is the watchdog opened via
* /dev/watchdog */
--
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