drivers/watchdog/sbc60xxwdt.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
8  *	any of this software. This material is provided "AS-IS" in
13  *           12/4 - 2000      [Initial revision]
14  *           25/4 - 2000      Added /dev/watchdog support
15  *           09/5 - 2001      [smj@oro.net] fixed fop_write to "return 1"
17  *           12/4 - 2002      [rob@osinvestor.com] eliminate fop_read
28  *           09/8 - 2003      [wim@iguana.be] cleanup of trailing spaces
37  *  This WDT driver is different from the other Linux WDT
40  *      particular WDT has a very short timeout (one second) and it
67  * You must set these - The driver cannot probe for the settings
72 MODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)");
76 MODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)");
122 	 * we agree to ping the WDT  in wdt_timer_ping()
125 		/* Ping the WDT by reading from wdt_start */  in wdt_timer_ping()
127 		/* Re-set the timer interval */  in wdt_timer_ping()
181 					return -EFAULT;  in fop_write()
198 		return -EBUSY;  in fop_open()
214 		pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");  in fop_close()
234 		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;  in fop_ioctl()
240 		int new_options, retval = -EINVAL;  in fop_ioctl()
242 			return -EFAULT;  in fop_ioctl()
260 			return -EFAULT;  in fop_ioctl()
263 			return -EINVAL;  in fop_ioctl()
272 		return -ENOTTY;  in fop_ioctl()
304  *	The WDT needs to learn about soft shutdowns in order to
327 	int rc = -EBUSY;  in sbc60xxwdt_init()
335 	if (!request_region(wdt_start, 1, "SBC 60XX WDT")) {  in sbc60xxwdt_init()
337 		rc = -EIO;  in sbc60xxwdt_init()
341 	/* We cannot reserve 0x45 - the kernel already has! */  in sbc60xxwdt_init()
343 		if (!request_region(wdt_stop, 1, "SBC 60XX WDT")) {  in sbc60xxwdt_init()
345 			rc = -EIO;  in sbc60xxwdt_init()
362 	pr_info("WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n",  in sbc60xxwdt_init()