drivers/watchdog/sun4v_wdt.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
3  *	sun4v watchdog timer
6  *	Implement a simple watchdog driver using the built-in sun4v hypervisor
7  *	watchdog support. If time expires, the hypervisor stops or bounces
18 #include <linux/watchdog.h>
27 static unsigned int timeout;  variable
28 module_param(timeout, uint, 0);
29 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
34 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
49 	 * HV watchdog timer will round up the timeout  in sun4v_wdt_ping()
51 	 * watchdog resolution in milliseconds.  in sun4v_wdt_ping()
53 	hverr = sun4v_mach_set_watchdog(wdd->timeout * 1000, NULL);  in sun4v_wdt_ping()
55 		return -EINVAL;  in sun4v_wdt_ping()
61 				 unsigned int timeout)  in sun4v_wdt_set_timeout()  argument
63 	wdd->timeout = timeout;  in sun4v_wdt_set_timeout()
72 	.identity =	"sun4v hypervisor watchdog",
89 	.timeout = WDT_TIMEOUT,
102 	 * domain for the watchdog.  in sun4v_wdt_init()
103 	 * watchdog-resolution  in sun4v_wdt_init()
104 	 * watchdog-max-timeout  in sun4v_wdt_init()
107 	 * serious is wrong. Correct to return -ENODEV here.  in sun4v_wdt_init()
112 		return -ENODEV;  in sun4v_wdt_init()
115 	err = -ENODEV;  in sun4v_wdt_init()
126 	/* Allow value of watchdog-resolution up to 1s (default) */  in sun4v_wdt_init()
127 	value = mdesc_get_property(handle, node, "watchdog-resolution", NULL);  in sun4v_wdt_init()
128 	err = -EINVAL;  in sun4v_wdt_init()
135 	value = mdesc_get_property(handle, node, "watchdog-max-timeout", NULL);  in sun4v_wdt_init()
138 		 * If the property value (in ms) is smaller than  in sun4v_wdt_init()
139 		 * min_timeout, return -EINVAL.  in sun4v_wdt_init()
146 		 * default max_timeout  then set watchdog max_timeout to  in sun4v_wdt_init()
153 	watchdog_init_timeout(&wdd, timeout, NULL);  in sun4v_wdt_init()
161 	pr_info("initialized (timeout=%ds, nowayout=%d)\n",  in sun4v_wdt_init()
162 		 wdd.timeout, nowayout);  in sun4v_wdt_init()
186 MODULE_DESCRIPTION("sun4v watchdog driver");