2 * Eurotech CPU-1220/1410 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@redhat.com>, All Rights Reserved.
12 * http://www.redhat.com
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 * 2002/04/25 - Rob Radez
31 * make __setup param unique
32 * proper options in watchdog_info
33 * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
34 * add expect_close support
36 * 2001 - Rodolfo Giometti
39 * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
40 * Added Matt Domsch's nowayout module option.
43 #include <linux/config.h>
44 #include <linux/interrupt.h>
45 #include <linux/module.h>
46 #include <linux/moduleparam.h>
47 #include <linux/types.h>
48 #include <linux/miscdevice.h>
49 #include <linux/watchdog.h>
51 #include <linux/ioport.h>
52 #include <linux/notifier.h>
53 #include <linux/reboot.h>
54 #include <linux/init.h>
57 #include <asm/uaccess.h>
58 #include <asm/system.h>
60 static unsigned long eurwdt_is_open;
61 static int eurwdt_timeout;
62 static char eur_expect_close;
65 * You must set these - there is no sane way to probe for this board.
66 * You can use eurwdt=x,y to set these now.
69 static int io = 0x3f0;
71 static char *ev = "int";
73 #define WDT_TIMEOUT 60 /* 1 minute */
75 #ifdef CONFIG_WATCHDOG_NOWAYOUT
76 static int nowayout = 1;
78 static int nowayout = 0;
81 module_param(nowayout, int, 0);
82 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_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, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
143 /* Setting interrupt line */
144 if (irq == 2 || irq > 15 || irq < 0) {
145 printk(KERN_ERR ": invalid irq number\n");
146 irq = 0; /* if invalid we disable interrupt */
149 printk(KERN_INFO ": interrupt disabled\n");
151 eurwdt_write_reg(WDT_TIMER_CFG, irq<<4);
153 eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
154 eurwdt_set_timeout(0); /* the default timeout */
162 static irqreturn_t eurwdt_interrupt(int irq, void *dev_id, struct pt_regs *regs)
164 printk(KERN_CRIT "timeout WDT timeout\n");
167 printk(KERN_CRIT "Would Reboot.\n");
169 printk(KERN_CRIT "Initiating system reboot.\n");
170 machine_restart(NULL);
179 * Reload counter one with the watchdog timeout.
182 static void eurwdt_ping(void)
184 /* Write the watchdog default value */
185 eurwdt_set_timeout(eurwdt_timeout);
190 * @file: file handle to the watchdog
191 * @buf: buffer to write (unused as data does not matter here
192 * @count: count of bytes
193 * @ppos: pointer to the position to write. No seeks allowed
195 * A write to a watchdog device is defined as a keepalive signal. Any
196 * write of data will do, as we we don't define content meaning.
199 static ssize_t eurwdt_write(struct file *file, const char *buf, size_t count,
202 /* Can't seek (pwrite) on this device */
203 if (ppos != &file->f_pos)
210 eur_expect_close = 0;
212 for (i = 0; i != count; i++) {
214 if(get_user(c, buf+i))
217 eur_expect_close = 42;
220 eurwdt_ping(); /* the default timeout */
228 * @inode: inode of the device
229 * @file: file handle to the device
230 * @cmd: watchdog command
231 * @arg: argument pointer
233 * The watchdog API defines a common set of functions for all watchdogs
234 * according to their available features.
237 static int eurwdt_ioctl(struct inode *inode, struct file *file,
238 unsigned int cmd, unsigned long arg)
240 static struct watchdog_info ident = {
241 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
242 .firmware_version = 1,
243 .identity = "WDT Eurotech CPU-1220/1410",
247 int options, retval = -EINVAL;
253 case WDIOC_GETSUPPORT:
254 return copy_to_user((struct watchdog_info *)arg, &ident,
255 sizeof(ident)) ? -EFAULT : 0;
257 case WDIOC_GETSTATUS:
258 case WDIOC_GETBOOTSTATUS:
259 return put_user(0, (int *) arg);
261 case WDIOC_KEEPALIVE:
265 case WDIOC_SETTIMEOUT:
266 if (copy_from_user(&time, (int *) arg, sizeof(int)))
270 if (time < 0 || time > 255)
273 eurwdt_timeout = time;
274 eurwdt_set_timeout(time);
277 case WDIOC_GETTIMEOUT:
278 return put_user(eurwdt_timeout, (int *)arg);
280 case WDIOC_SETOPTIONS:
281 if (get_user(options, (int *)arg))
283 if (options & WDIOS_DISABLECARD) {
284 eurwdt_disable_timer();
287 if (options & WDIOS_ENABLECARD) {
288 eurwdt_activate_timer();
298 * @inode: inode of device
299 * @file: file handle to device
301 * The misc device has been opened. The watchdog device is single
302 * open and on opening we load the counter.
305 static int eurwdt_open(struct inode *inode, struct file *file)
307 if (test_and_set_bit(0, &eurwdt_is_open))
309 eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
310 /* Activate the WDT */
311 eurwdt_activate_timer();
317 * @inode: inode to board
318 * @file: file handle to board
320 * The watchdog has a configurable API. There is a religious dispute
321 * between people who want their watchdog to be able to shut down and
322 * those who want to be sure if the watchdog manager dies the machine
323 * reboots. In the former case we disable the counters, in the latter
324 * case you have to open it again very soon.
327 static int eurwdt_release(struct inode *inode, struct file *file)
329 if (eur_expect_close == 42) {
330 eurwdt_disable_timer();
332 printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n");
335 clear_bit(0, &eurwdt_is_open);
336 eur_expect_close = 0;
342 * @this: our notifier block
343 * @code: the event being reported
346 * Our notifier is called on system shutdowns. We want to turn the card
347 * off at reboot otherwise the machine will reboot again during memory
348 * test or worse yet during the following fsck. This would suck, in fact
349 * trust me - if it happens it does suck.
352 static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
355 if (code == SYS_DOWN || code == SYS_HALT) {
356 /* Turn the card off */
357 eurwdt_disable_timer();
368 static struct file_operations eurwdt_fops = {
369 .owner = THIS_MODULE,
371 .write = eurwdt_write,
372 .ioctl = eurwdt_ioctl,
374 .release = eurwdt_release,
377 static struct miscdevice eurwdt_miscdev = {
378 .minor = WATCHDOG_MINOR,
380 .fops = &eurwdt_fops,
384 * The WDT card needs to learn about soft shutdowns in order to
385 * turn the timebomb registers off.
388 static struct notifier_block eurwdt_notifier = {
389 .notifier_call = eurwdt_notify_sys,
395 * Unload the watchdog. You cannot do this with any file handles open.
396 * If your watchdog is set to continue ticking on close and you unload
397 * it, well it keeps ticking. We won't get the interrupt but the board
398 * will not touch PC memory so all is fine. You just have to load a new
399 * module in 60 seconds or reboot.
402 static void __exit eurwdt_exit(void)
406 misc_deregister(&eurwdt_miscdev);
408 unregister_reboot_notifier(&eurwdt_notifier);
409 release_region(io, 2);
416 * Set up the WDT watchdog board. After grabbing the resources
417 * we require we need also to unlock the device.
418 * The open() function will actually kick the board off.
421 static int __init eurwdt_init(void)
425 ret = misc_register(&eurwdt_miscdev);
427 printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
432 ret = request_irq(irq, eurwdt_interrupt, SA_INTERRUPT, "eurwdt", NULL);
434 printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
438 if (!request_region(io, 2, "eurwdt")) {
439 printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
444 ret = register_reboot_notifier(&eurwdt_notifier);
446 printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);
450 eurwdt_unlock_chip();
453 printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
454 " - timeout event: %s\n",
455 io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
461 release_region(io, 2);
467 misc_deregister(&eurwdt_miscdev);
471 module_init(eurwdt_init);
472 module_exit(eurwdt_exit);
474 MODULE_AUTHOR("Rodolfo Giometti");
475 MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
476 MODULE_LICENSE("GPL");
477 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);