drivers/watchdog/w83877f_wdt.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
3  *	W83877F Computer Watchdog Timer driver
9  *	any of this software. This material is provided "AS-IS" in
14  *           4/19 - 2001      [Initial revision]
15  *           9/27 - 2001      Added spinlocking
16  *           4/12 - 2002      [rob@osinvestor.com] Eliminate extra comments
27  *           09/8 - 2003      [wim@iguana.be] cleanup of trailing spaces
35  *  drivers in that the driver will ping the watchdog by itself,
46 #include <linux/timer.h>
49 #include <linux/watchdog.h>
70  * EMACS PC-104 board I'm using). If we reset the watchdog every
78  * char to /dev/watchdog every 30 seconds.
86 	"Watchdog timeout in seconds. (1<=timeout<=3600, default="
93 		"Watchdog cannot be stopped once started (default="
97 static DEFINE_TIMER(timer, wdt_timer_ping);
119 		/* Re-set the timer interval */  in wdt_timer_ping()
120 		mod_timer(&timer, jiffies + WDT_INTERVAL);  in wdt_timer_ping()
125 		pr_warn("Heartbeat lost! Will not ping the watchdog\n");  in wdt_timer_ping()
144 	/* enable watchdog */  in wdt_change()
158 	/* Start the timer */  in wdt_startup()
159 	mod_timer(&timer, jiffies + WDT_INTERVAL);  in wdt_startup()
163 	pr_info("Watchdog timer is now enabled\n");  in wdt_startup()
168 	/* Stop the timer */  in wdt_turnoff()
169 	del_timer_sync(&timer);  in wdt_turnoff()
173 	pr_info("Watchdog timer is now disabled...\n");  in wdt_turnoff()
183  * /dev/watchdog handling
189 	/* See if we got the magic character 'V' and reload the timer */  in fop_write()
203 					return -EFAULT;  in fop_write()
209 		/* someone wrote to us, we should restart timer */  in fop_write()
219 		return -EBUSY;  in fop_open()
231 		del_timer(&timer);  in fop_close()
252 		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;  in fop_ioctl()
258 		int new_options, retval = -EINVAL;  in fop_ioctl()
261 			return -EFAULT;  in fop_ioctl()
283 			return -EFAULT;  in fop_ioctl()
287 			return -EINVAL;  in fop_ioctl()
296 		return -ENOTTY;  in fop_ioctl()
311 	.name	= "watchdog",
350 	int rc = -EBUSY;  in w83877f_wdt_init()
361 		rc = -EIO;  in w83877f_wdt_init()
367 		rc = -EIO;  in w83877f_wdt_init()
403 MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip");