1 // SPDX-License-Identifier: GPL-2.0-or-later
9  *	any of this software. This material is provided "AS-IS" in
12  *	(C) Copyright 2003-2006  Sven Anders <anders@anduras.de>
15  *	2003 - Created version 1.0 for Linux 2.4.x.
16  *	2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE
22  *	reset the computer system in case of a software fault.
30  *	for yet another little while to reset the system.
33  *	reset the system (causing a reboot) after the timeout occurs.
38  * For an example userspace keep-alive daemon, see:
56 #include <linux/io.h>
82 static DEFINE_SPINLOCK(io_lock);/* to guard the watchdog from io races */
86 /* -- Low level function ----------------------------------------*/
88 /* unlock the IO chip */
97 /* lock the IO chip */
103 /* select the IO device */
124 /* -- Medium level functions ------------------------------------*/
128 	/* -- General Purpose I/O Bit 1.2 --  in gpio_bit12()
142 	/* -- General Purpose I/O Bit 1.3 --  in gpio_bit13()
147 	 * Bit 4-6 (Reserved)  in gpio_bit13()
155 	/* -- Watchdog timer units --  in wdt_timer_units()
156 	 * Bit 0-6 (Reserved)  in wdt_timer_units()
157 	 * Bit 7,  WDT Time-out Value Units Select  in wdt_timer_units()
165 	/* -- Watchdog Timer Time-out Value --  in wdt_timeout_value()
166 	 * Bit 0-7 Binary coded units (0=Disabled, 1..255)  in wdt_timeout_value()
173 	/* -- Watchdog timer configuration --  in wdt_timer_conf()
174 	 * Bit 0   Joystick enable: 0* = No Reset, 1 = Reset WDT upon  in wdt_timer_conf()
176 	 * Bit 1   Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.  in wdt_timer_conf()
177 	 * Bit 2   Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr  in wdt_timer_conf()
178 	 * Bit 3   Reset the timer  in wdt_timer_conf()
181 	 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,  in wdt_timer_conf()
189 	/* -- Watchdog timer control --  in wdt_timer_ctrl()
192 	 * Bit 2   Force Timeout: 1 = Forces WD timeout event (self-cleaning)  in wdt_timer_ctrl()
198 	 * -- Soft power management --  in wdt_timer_ctrl()
200 	 *            set via register 0xB8, (self-cleaning)  in wdt_timer_ctrl()
203 	 *            set via register 0xB8, (self-cleaning)  in wdt_timer_ctrl()
204 	 * Bit 7   SPOFF: 1 = Force software power down (self-cleaning)  in wdt_timer_ctrl()
209 /* -- Higher level functions ------------------------------------*/
228 	/* reset control register */  in wb_smsc_wdt_initialize()
231 	/* reset configuration register */  in wb_smsc_wdt_initialize()
258 	/* reset watchdog config register */  in wb_smsc_wdt_shutdown()
261 	/* reset watchdog control register */  in wb_smsc_wdt_shutdown()
321 /* reset the timer */
329 	/* reset the timer */  in wb_smsc_wdt_reset_timer()
345 /* -- File operations -------------------------------------------*/
354 		return -EBUSY;  in wb_smsc_wdt_open()
362 	pr_info("Watchdog enabled. Timeout set to %d %s\n",  in wb_smsc_wdt_open()
376 		pr_info("Watchdog disabled, sleeping again...\n");  in wb_smsc_wdt_release()
378 		pr_crit("Unexpected close, not stopping watchdog!\n");  in wb_smsc_wdt_release()
397 			/* reset expect flag */  in wb_smsc_wdt_write()
405 					return -EFAULT;  in wb_smsc_wdt_write()
442 								? -EFAULT : 0;  in wb_smsc_wdt_ioctl()
449 		int options, retval = -EINVAL;  in wb_smsc_wdt_ioctl()
452 			return -EFAULT;  in wb_smsc_wdt_ioctl()
469 			return -EFAULT;  in wb_smsc_wdt_ioctl()
474 			return -EINVAL;  in wb_smsc_wdt_ioctl()
484 		return -ENOTTY;  in wb_smsc_wdt_ioctl()
488 /* -- Notifier funtions -----------------------------------------*/
494 		/* set timeout to 0, to avoid possible race-condition */  in wb_smsc_wdt_notify_sys()
501 /* -- Module's structures ---------------------------------------*/
523 /* -- Module init functions -------------------------------------*/
532 		VERSION " initialising...\n");  in wb_smsc_wdt_init()
535 		pr_err("Unable to register IO port %#x\n", IOPORT);  in wb_smsc_wdt_init()
536 		ret = -EBUSY;  in wb_smsc_wdt_init()
549 		pr_err("Unable to register reboot notifier err = %d\n", ret);  in wb_smsc_wdt_init()
555 		pr_err("Unable to register miscdev on minor %d\n",  in wb_smsc_wdt_init()
561 	pr_info("Timeout set to %d %s\n",  in wb_smsc_wdt_init()
563 	pr_info("Watchdog initialized and sleeping (nowayout=%d)...\n",  in wb_smsc_wdt_init()
585 		pr_info("Watchdog disabled\n");  in wb_smsc_wdt_exit()
592 	pr_info("SMsC 37B787 watchdog component driver removed\n");  in wb_smsc_wdt_exit()
610 MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");