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authorWim Van Sebroeck <wim@iguana.be>2011-07-22 22:56:38 +0400
committerWim Van Sebroeck <wim@iguana.be>2011-07-28 12:01:05 +0400
commit2fa03560ab3a6dd83cad9bfd5692179fc2ceabb3 (patch)
treeb208649368917b6c8d16c5cc737b2b83e906d074
parent43316044d4f64da008d6aca7d4b60771b9a24eb8 (diff)
downloadlinux-2fa03560ab3a6dd83cad9bfd5692179fc2ceabb3.tar.xz
watchdog: WatchDog Timer Driver Core - Add basic ioctl functionality
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@lxorguk.ukuu.org.uk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
-rw-r--r--Documentation/watchdog/watchdog-kernel-api.txt6
-rw-r--r--drivers/watchdog/watchdog_dev.c32
-rw-r--r--include/linux/watchdog.h4
3 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 3db67e74b80e..2bdc6dc6e04c 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -41,6 +41,7 @@ The watchdog device structure looks like this:
struct watchdog_device {
const struct watchdog_info *info;
const struct watchdog_ops *ops;
+ unsigned int bootstatus;
void *driver_data;
unsigned long status;
};
@@ -49,6 +50,8 @@ It contains following fields:
* 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.
+* bootstatus: status of the device after booting (reported with watchdog
+ WDIOF_* status bits).
* driver_data: a pointer to the drivers private data of a watchdog device.
This data should only be accessed via the watchdog_set_drvadata and
watchdog_get_drvdata routines.
@@ -65,6 +68,7 @@ struct watchdog_ops {
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
+ unsigned int (*status)(struct watchdog_device *);
};
It is important that you first define the module owner of the watchdog timer
@@ -97,6 +101,8 @@ they are supported. These optional routines/operations are:
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 bits that are defined are:
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 366f49ce69b8..00a611293065 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -95,6 +95,37 @@ static ssize_t watchdog_write(struct file *file, const char __user *data,
}
/*
+ * 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;
+ unsigned int val;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, wdd->info,
+ sizeof(struct watchdog_info)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ val = wdd->ops->status ? wdd->ops->status(wdd) : 0;
+ return put_user(val, p);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(wdd->bootstatus, p);
+ default:
+ return -ENOTTY;
+ }
+}
+
+/*
* watchdog_open: open the /dev/watchdog device.
* @inode: inode of device
* @file: file handle to device
@@ -163,6 +194,7 @@ static int watchdog_release(struct inode *inode, struct file *file)
static const struct file_operations watchdog_fops = {
.owner = THIS_MODULE,
.write = watchdog_write,
+ .unlocked_ioctl = watchdog_ioctl,
.open = watchdog_open,
.release = watchdog_release,
};
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 5ab31bfd2906..29ff80807dd4 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -68,6 +68,7 @@ struct watchdog_device;
* @start: The routine for starting the watchdog device.
* @stop: The routine for stopping the watchdog device.
* @ping: The routine that sends a keepalive ping to the watchdog device.
+ * @status: The routine that shows the status of the watchdog device.
*
* The watchdog_ops structure contains a list of low-level operations
* that control a watchdog device. It also contains the module that owns
@@ -81,12 +82,14 @@ struct watchdog_ops {
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
+ unsigned int (*status)(struct watchdog_device *);
};
/** struct watchdog_device - The structure that defines a watchdog device
*
* @info: Pointer to a watchdog_info structure.
* @ops: Pointer to the list of watchdog operations.
+ * @bootstatus: Status of the watchdog device at boot.
* @driver-data:Pointer to the drivers private data.
* @status: Field that contains the devices internal status bits.
*
@@ -99,6 +102,7 @@ struct watchdog_ops {
struct watchdog_device {
const struct watchdog_info *info;
const struct watchdog_ops *ops;
+ unsigned int bootstatus;
void *driver_data;
unsigned long status;
/* Bit numbers for status flags */