2 * Eurotech CPU-1220/1410/1420 on board WDT driver
4 * (c) Copyright 2001 Ascensit <support@ascensit.com>
5 * (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com>
6 * (c) Copyright 2002 Rob Radez <rob@osinvestor.com>
9 * Original copyright messages:
11 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
12 * All Rights Reserved.
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
19 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
20 * warranty for any of this software. This material is provided
21 * "AS-IS" and at no charge.
23 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>*
28 * 2001 - Rodolfo Giometti
31 * 2002/04/25 - Rob Radez
34 * make __setup param unique
35 * proper options in watchdog_info
36 * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
37 * add expect_close support
39 * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
40 * Added Matt Domsch's nowayout module option.
44 * The eurotech CPU-1220/1410/1420's watchdog is a part
45 * of the on-board SUPER I/O device SMSC FDC 37B782.
48 #include <linux/interrupt.h>
49 #include <linux/module.h>
50 #include <linux/moduleparam.h>
51 #include <linux/types.h>
52 #include <linux/miscdevice.h>
53 #include <linux/watchdog.h>
55 #include <linux/ioport.h>
56 #include <linux/notifier.h>
57 #include <linux/reboot.h>
58 #include <linux/init.h>
60 #include <linux/uaccess.h>
63 static unsigned long eurwdt_is_open;
64 static int eurwdt_timeout;
65 static char eur_expect_close;
66 static DEFINE_SPINLOCK(eurwdt_lock);
69 * You must set these - there is no sane way to probe for this board.
72 static int io = 0x3f0;
74 static char *ev = "int";
76 #define WDT_TIMEOUT 60 /* 1 minute */
78 static int nowayout = WATCHDOG_NOWAYOUT;
79 module_param(nowayout, int, 0);
80 MODULE_PARM_DESC(nowayout,
81 "Watchdog cannot be stopped once started (default="
82 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
88 #define WDT_CTRL_REG 0x30
89 #define WDT_OUTPIN_CFG 0xe2
90 #define WDT_EVENT_INT 0x00
91 #define WDT_EVENT_REBOOT 0x08
92 #define WDT_UNIT_SEL 0xf1
93 #define WDT_UNIT_SECS 0x80
94 #define WDT_TIMEOUT_VAL 0xf2
95 #define WDT_TIMER_CFG 0xf3
98 module_param(io, int, 0);
99 MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
100 module_param(irq, int, 0);
101 MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
102 module_param(ev, charp, 0);
103 MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
107 * Programming support
110 static inline void eurwdt_write_reg(u8 index, u8 data)
116 static inline void eurwdt_lock_chip(void)
121 static inline void eurwdt_unlock_chip(void)
124 eurwdt_write_reg(0x07, 0x08); /* set the logical device */
127 static inline void eurwdt_set_timeout(int timeout)
129 eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
132 static inline void eurwdt_disable_timer(void)
134 eurwdt_set_timeout(0);
137 static void eurwdt_activate_timer(void)
139 eurwdt_disable_timer();
140 eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
141 eurwdt_write_reg(WDT_OUTPIN_CFG,
142 !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
144 /* Setting interrupt line */
145 if (irq == 2 || irq > 15 || irq < 0) {
146 printk(KERN_ERR ": invalid irq number\n");
147 irq = 0; /* if invalid we disable interrupt */
150 printk(KERN_INFO ": interrupt disabled\n");
152 eurwdt_write_reg(WDT_TIMER_CFG, irq << 4);
154 eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
155 eurwdt_set_timeout(0); /* the default timeout */
163 static irqreturn_t eurwdt_interrupt(int irq, void *dev_id)
165 printk(KERN_CRIT "timeout WDT timeout\n");
168 printk(KERN_CRIT "Would Reboot.\n");
170 printk(KERN_CRIT "Initiating system reboot.\n");
180 * Reload counter one with the watchdog timeout.
183 static void eurwdt_ping(void)
185 /* Write the watchdog default value */
186 eurwdt_set_timeout(eurwdt_timeout);
191 * @file: file handle to the watchdog
192 * @buf: buffer to write (unused as data does not matter here
193 * @count: count of bytes
194 * @ppos: pointer to the position to write. No seeks allowed
196 * A write to a watchdog device is defined as a keepalive signal. Any
197 * write of data will do, as we we don't define content meaning.
200 static ssize_t eurwdt_write(struct file *file, const char __user *buf,
201 size_t count, loff_t *ppos)
207 eur_expect_close = 0;
209 for (i = 0; i != count; i++) {
211 if (get_user(c, buf + i))
214 eur_expect_close = 42;
217 spin_lock(&eurwdt_lock);
218 eurwdt_ping(); /* the default timeout */
219 spin_unlock(&eurwdt_lock);
226 * @file: file handle to the device
227 * @cmd: watchdog command
228 * @arg: argument pointer
230 * The watchdog API defines a common set of functions for all watchdogs
231 * according to their available features.
234 static long eurwdt_ioctl(struct file *file,
235 unsigned int cmd, unsigned long arg)
237 void __user *argp = (void __user *)arg;
238 int __user *p = argp;
239 static const struct watchdog_info ident = {
240 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
242 .firmware_version = 1,
243 .identity = "WDT Eurotech CPU-1220/1410",
247 int options, retval = -EINVAL;
250 case WDIOC_GETSUPPORT:
251 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
253 case WDIOC_GETSTATUS:
254 case WDIOC_GETBOOTSTATUS:
255 return put_user(0, p);
257 case WDIOC_SETOPTIONS:
258 if (get_user(options, p))
260 spin_lock(&eurwdt_lock);
261 if (options & WDIOS_DISABLECARD) {
262 eurwdt_disable_timer();
265 if (options & WDIOS_ENABLECARD) {
266 eurwdt_activate_timer();
270 spin_unlock(&eurwdt_lock);
273 case WDIOC_KEEPALIVE:
274 spin_lock(&eurwdt_lock);
276 spin_unlock(&eurwdt_lock);
279 case WDIOC_SETTIMEOUT:
280 if (copy_from_user(&time, p, sizeof(int)))
284 if (time < 0 || time > 255)
287 spin_lock(&eurwdt_lock);
288 eurwdt_timeout = time;
289 eurwdt_set_timeout(time);
290 spin_unlock(&eurwdt_lock);
293 case WDIOC_GETTIMEOUT:
294 return put_user(eurwdt_timeout, p);
303 * @inode: inode of device
304 * @file: file handle to device
306 * The misc device has been opened. The watchdog device is single
307 * open and on opening we load the counter.
310 static int eurwdt_open(struct inode *inode, struct file *file)
312 if (test_and_set_bit(0, &eurwdt_is_open))
314 eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
315 /* Activate the WDT */
316 eurwdt_activate_timer();
317 return nonseekable_open(inode, file);
322 * @inode: inode to board
323 * @file: file handle to board
325 * The watchdog has a configurable API. There is a religious dispute
326 * between people who want their watchdog to be able to shut down and
327 * those who want to be sure if the watchdog manager dies the machine
328 * reboots. In the former case we disable the counters, in the latter
329 * case you have to open it again very soon.
332 static int eurwdt_release(struct inode *inode, struct file *file)
334 if (eur_expect_close == 42)
335 eurwdt_disable_timer();
338 "eurwdt: Unexpected close, not stopping watchdog!\n");
341 clear_bit(0, &eurwdt_is_open);
342 eur_expect_close = 0;
348 * @this: our notifier block
349 * @code: the event being reported
352 * Our notifier is called on system shutdowns. We want to turn the card
353 * off at reboot otherwise the machine will reboot again during memory
354 * test or worse yet during the following fsck. This would suck, in fact
355 * trust me - if it happens it does suck.
358 static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
361 if (code == SYS_DOWN || code == SYS_HALT)
362 eurwdt_disable_timer(); /* Turn the card off */
372 static const struct file_operations eurwdt_fops = {
373 .owner = THIS_MODULE,
375 .write = eurwdt_write,
376 .unlocked_ioctl = eurwdt_ioctl,
378 .release = eurwdt_release,
381 static struct miscdevice eurwdt_miscdev = {
382 .minor = WATCHDOG_MINOR,
384 .fops = &eurwdt_fops,
388 * The WDT card needs to learn about soft shutdowns in order to
389 * turn the timebomb registers off.
392 static struct notifier_block eurwdt_notifier = {
393 .notifier_call = eurwdt_notify_sys,
399 * Unload the watchdog. You cannot do this with any file handles open.
400 * If your watchdog is set to continue ticking on close and you unload
401 * it, well it keeps ticking. We won't get the interrupt but the board
402 * will not touch PC memory so all is fine. You just have to load a new
403 * module in 60 seconds or reboot.
406 static void __exit eurwdt_exit(void)
410 misc_deregister(&eurwdt_miscdev);
412 unregister_reboot_notifier(&eurwdt_notifier);
413 release_region(io, 2);
420 * Set up the WDT watchdog board. After grabbing the resources
421 * we require we need also to unlock the device.
422 * The open() function will actually kick the board off.
425 static int __init eurwdt_init(void)
429 ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL);
431 printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
435 if (!request_region(io, 2, "eurwdt")) {
436 printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
441 ret = register_reboot_notifier(&eurwdt_notifier);
444 "eurwdt: can't register reboot notifier (err=%d)\n", ret);
448 ret = misc_register(&eurwdt_miscdev);
450 printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
455 eurwdt_unlock_chip();
458 printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
459 " - timeout event: %s\n",
460 io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
466 unregister_reboot_notifier(&eurwdt_notifier);
469 release_region(io, 2);
476 module_init(eurwdt_init);
477 module_exit(eurwdt_exit);
479 MODULE_AUTHOR("Rodolfo Giometti");
480 MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
481 MODULE_LICENSE("GPL");
482 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);