path: root/Documentation/watchdog
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authorWim Van Sebroeck <wim@iguana.be>2011-07-22 18:58:21 +0000
committerWim Van Sebroeck <wim@iguana.be>2011-07-28 08:01:11 +0000
commit014d694e5d59e4219803cd14deaae496d86e4910 (patch)
treec79d00c812b6f01fc477318cbcc003e2826f9f24 /Documentation/watchdog
parent234445b4e4542f3e0f216459245ab369a18adcf2 (diff)
watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl
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>
Diffstat (limited to 'Documentation/watchdog')
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 429f81bf0cf..acdee39fb08 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -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: