1 // SPDX-License-Identifier: GPL-2.0+
5  *	(c) Copyright 2008-2011 Alan Cox <[email protected]>,
8  *	(c) Copyright 2008-2011 Wim Van Sebroeck <[email protected]>.
22  *	This material is provided "AS-IS" and at no charge.
29 #include <linux/errno.h>	/* For the -ENODEV/... values */
46 static int stop_on_reboot = -1;
69 	list_add_tail(&wdd->deferred,  in watchdog_deferred_registration_add()
82 			list_del(&wdd_tmp->deferred);  in watchdog_deferred_registration_del()
91 	 * Check that we have valid min and max timeout values, if  in watchdog_check_min_max_timeout()
94 	if (!wdd->max_hw_heartbeat_ms && wdd->min_timeout > wdd->max_timeout) {  in watchdog_check_min_max_timeout()
95 		pr_info("Invalid min and max timeout values, resetting to 0!\n");  in watchdog_check_min_max_timeout()
96 		wdd->min_timeout = 0;  in watchdog_check_min_max_timeout()
97 		wdd->max_timeout = 0;  in watchdog_check_min_max_timeout()
102  * watchdog_init_timeout() - initialize the timeout field
104  * @timeout_parm: timeout module parameter
105  * @dev: Device that stores the timeout-sec property
107  * Initialize the timeout field of the watchdog_device struct with either the
108  * timeout module parameter (if it is valid value) or the timeout-sec property
111  * be the default timeout value). Note that for the module parameter, '0' means
112  * 'use default' while it is an invalid value for the timeout-sec property.
115  * A zero is returned on success or -EINVAL if all provided values are out of
121 	const char *dev_str = wdd->parent ? dev_name(wdd->parent) :  in watchdog_init_timeout()
122 			      (const char *)wdd->info->identity;  in watchdog_init_timeout()
131 			wdd->timeout = timeout_parm;  in watchdog_init_timeout()
134 		pr_err("%s: driver supplied timeout (%u) out of range\n",  in watchdog_init_timeout()
136 		ret = -EINVAL;  in watchdog_init_timeout()
140 	if (dev && dev->of_node &&  in watchdog_init_timeout()
141 	    of_property_read_u32(dev->of_node, "timeout-sec", &t) == 0) {  in watchdog_init_timeout()
143 			wdd->timeout = t;  in watchdog_init_timeout()
146 		pr_err("%s: DT supplied timeout (%u) out of range\n", dev_str, t);  in watchdog_init_timeout()
147 		ret = -EINVAL;  in watchdog_init_timeout()
150 	if (ret < 0 && wdd->timeout)  in watchdog_init_timeout()
151 		pr_warn("%s: falling back to default timeout (%u)\n", dev_str,  in watchdog_init_timeout()
152 			wdd->timeout);  in watchdog_init_timeout()
168 			ret = wdd->ops->stop(wdd);  in watchdog_reboot_notifier()
186 	ret = wdd->ops->restart(wdd, action, data);  in watchdog_restart_notifier()
221  * watchdog_set_restart_priority - Change priority of restart handler
230  * If a wdd->ops->restart function is provided when watchdog_register_device is
236 	wdd->restart_nb.priority = priority;  in watchdog_set_restart_priority()
242 	int ret, id = -1;  in ___watchdog_register_device()
244 	if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)  in ___watchdog_register_device()
245 		return -EINVAL;  in ___watchdog_register_device()
248 	if (!wdd->ops->start || (!wdd->ops->stop && !wdd->max_hw_heartbeat_ms))  in ___watchdog_register_device()
249 		return -EINVAL;  in ___watchdog_register_device()
260 	if (wdd->parent) {  in ___watchdog_register_device()
261 		ret = of_alias_get_id(wdd->parent->of_node, "watchdog");  in ___watchdog_register_device()
268 		id = ida_alloc_max(&watchdog_ida, MAX_DOGS - 1, GFP_KERNEL);  in ___watchdog_register_device()
272 	wdd->id = id;  in ___watchdog_register_device()
277 		if (!(id == 0 && ret == -EBUSY))  in ___watchdog_register_device()
281 		id = ida_alloc_range(&watchdog_ida, 1, MAX_DOGS - 1,  in ___watchdog_register_device()
285 		wdd->id = id;  in ___watchdog_register_device()
295 	if (stop_on_reboot != -1) {  in ___watchdog_register_device()
297 			set_bit(WDOG_STOP_ON_REBOOT, &wdd->status);  in ___watchdog_register_device()
299 			clear_bit(WDOG_STOP_ON_REBOOT, &wdd->status);  in ___watchdog_register_device()
302 	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {  in ___watchdog_register_device()
303 		if (!wdd->ops->stop)  in ___watchdog_register_device()
304 			pr_warn("watchdog%d: stop_on_reboot not supported\n", wdd->id);  in ___watchdog_register_device()
306 			wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;  in ___watchdog_register_device()
308 			ret = register_reboot_notifier(&wdd->reboot_nb);  in ___watchdog_register_device()
311 					wdd->id, ret);  in ___watchdog_register_device()
319 	if (wdd->ops->restart) {  in ___watchdog_register_device()
320 		wdd->restart_nb.notifier_call = watchdog_restart_notifier;  in ___watchdog_register_device()
322 		ret = register_restart_handler(&wdd->restart_nb);  in ___watchdog_register_device()
325 				wdd->id, ret);  in ___watchdog_register_device()
328 	if (test_bit(WDOG_NO_PING_ON_SUSPEND, &wdd->status)) {  in ___watchdog_register_device()
329 		wdd->pm_nb.notifier_call = watchdog_pm_notifier;  in ___watchdog_register_device()
331 		ret = register_pm_notifier(&wdd->pm_nb);  in ___watchdog_register_device()
334 				wdd->id, ret);  in ___watchdog_register_device()
347 		dev_str = wdd->parent ? dev_name(wdd->parent) :  in __watchdog_register_device()
348 			  (const char *)wdd->info->identity;  in __watchdog_register_device()
357  * watchdog_register_device() - register a watchdog device
387 	if (wdd->ops->restart)  in __watchdog_unregister_device()
388 		unregister_restart_handler(&wdd->restart_nb);  in __watchdog_unregister_device()
390 	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status))  in __watchdog_unregister_device()
391 		unregister_reboot_notifier(&wdd->reboot_nb);  in __watchdog_unregister_device()
394 	ida_free(&watchdog_ida, wdd->id);  in __watchdog_unregister_device()
398  * watchdog_unregister_device() - unregister a watchdog device
423  * devm_watchdog_register_device() - resource managed watchdog_register_device()
440 		return -ENOMEM;  in devm_watchdog_register_device()
463 		list_del(&wdd->deferred);  in watchdog_deferred_registration()