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watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl

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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@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>
This commit is contained in:
Wim Van Sebroeck 2011-07-22 18:58:21 +00:00
parent 234445b4e4
commit 014d694e5d
3 changed files with 34 additions and 0 deletions
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10
Documentation/watchdog/watchdog-kernel-api.txt
View File

@ -42,6 +42,7 @@ struct watchdog_device {
const struct watchdog_info *info;
const struct watchdog_ops *ops;
unsigned int bootstatus;
unsigned int timeout;
void *driver_data;
unsigned long status;
};
@ -50,6 +51,7 @@ 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.
* timeout: the watchdog timer's timeout value (in seconds).
* 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.
@ -70,6 +72,7 @@ struct watchdog_ops {
/* optional operations */
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
};
It is important that you first define the module owner of the watchdog timer
@ -107,6 +110,13 @@ they are supported. These optional routines/operations are:
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, -EINVAL for "parameter out of range"
and -EIO for "could not write value to the watchdog". 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 bits that are defined are:

20
drivers/watchdog/watchdog_dev.c
View File

@ -190,6 +190,26 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
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 send 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 == 0)
return -EOPNOTSUPP;
return put_user(wdd->timeout, p);
default:
return -ENOTTY;
}

4
include/linux/watchdog.h
View File

@ -69,6 +69,7 @@ struct 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.
* @set_timeout:The routine for setting the watchdog devices timeout value.
*
* The watchdog_ops structure contains a list of low-level operations
* that control a watchdog device. It also contains the module that owns
@ -83,6 +84,7 @@ struct watchdog_ops {
/* optional operations */
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
};
/** struct watchdog_device - The structure that defines a watchdog device
@ -90,6 +92,7 @@ struct watchdog_ops {
* @info: Pointer to a watchdog_info structure.
* @ops: Pointer to the list of watchdog operations.
* @bootstatus: Status of the watchdog device at boot.
* @timeout: The watchdog devices timeout value.
* @driver-data:Pointer to the drivers private data.
* @status: Field that contains the devices internal status bits.
*
@ -103,6 +106,7 @@ struct watchdog_device {
const struct watchdog_info *info;
const struct watchdog_ops *ops;
unsigned int bootstatus;
unsigned int timeout;
void *driver_data;
unsigned long status;
/* Bit numbers for status flags */