/**
* watchdog_register_device() - register a watchdog device
* @wdd: watchdog device
*
* Register a watchdog device with the kernel so that the
* watchdog timer can be accessed from userspace.
*
* A zero is returned on success and a negative errno code for
* failure.
*/
int watchdog_register_device(struct watchdog_device *wdd)
{
int ret, id, devno;
if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
return -EINVAL;
/* Mandatory operations need to be supported */
if (wdd->ops->start == NULL || wdd->ops->stop == NULL)
return -EINVAL;
watchdog_check_min_max_timeout(wdd);
/*
* Note: now that all watchdog_device data has been verified, we
* will not check this anymore in other functions. If data gets
* corrupted in a later stage then we expect a kernel panic!
*/
mutex_init(&wdd->lock);
id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
if (id < 0)
return id;
wdd->id = id;
ret = watchdog_dev_register(wdd);
if (ret) {
ida_simple_remove(&watchdog_ida, id);
if (!(id == 0 && ret == -EBUSY))
return ret;
/* Retry in case a legacy watchdog module exists */
id = ida_simple_get(&watchdog_ida, 1, MAX_DOGS, GFP_KERNEL);
if (id < 0)
return id;
wdd->id = id;
ret = watchdog_dev_register(wdd);
if (ret) {
ida_simple_remove(&watchdog_ida, id);
return ret;
}
}
devno = wdd->cdev.dev;
wdd->dev = device_create(watchdog_class, wdd->parent, devno,
NULL, "watchdog%d", wdd->id);
if (IS_ERR(wdd->dev)) {
watchdog_dev_unregister(wdd);
ida_simple_remove(&watchdog_ida, id);
ret = PTR_ERR(wdd->dev);
return ret;
}
return 0;
}
/**
* watchdog_register_device() - register a watchdog device
* @wdd: watchdog device
*
* Register a watchdog device with the kernel so that the
* watchdog timer can be accessed from userspace.
*
* A zero is returned on success and a negative errno code for
* failure.
*/
int watchdog_register_device(struct watchdog_device *wdd)
{
int ret;
if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
return -EINVAL;
/* Mandatory operations need to be supported */
if (wdd->ops->start == NULL || wdd->ops->stop == NULL)
return -EINVAL;
/*
* Check that we have valid min and max timeout values, if
* not reset them both to 0 (=not used or unknown)
*/
if (wdd->min_timeout > wdd->max_timeout) {
pr_info("Invalid min and max timeout values, resetting to 0!\n");
wdd->min_timeout = 0;
wdd->max_timeout = 0;
}
/*
* Note: now that all watchdog_device data has been verified, we
* will not check this anymore in other functions. If data gets
* corrupted in a later stage then we expect a kernel panic!
*/
/* We only support 1 watchdog device via the /dev/watchdog interface */
ret = watchdog_dev_register(wdd);
if (ret) {
pr_err("error registering /dev/watchdog (err=%d).\n", ret);
return ret;
}
return 0;
}
