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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50 #include <linux/interrupt.h>
51 #include <linux/module.h>
52 #include <linux/moduleparam.h>
53 #include <linux/types.h>
54 #include <linux/miscdevice.h>
55 #include <linux/watchdog.h>
57 #include <linux/ioport.h>
58 #include <linux/notifier.h>
59 #include <linux/reboot.h>
60 #include <linux/init.h>
62 #include <linux/uaccess.h>
64 #include <asm/system.h>
66 static unsigned long eurwdt_is_open;
67 static int eurwdt_timeout;
68 static char eur_expect_close;
69 static DEFINE_SPINLOCK(eurwdt_lock);
72 * You must set these - there is no sane way to probe for this board.
75 static int io = 0x3f0;
77 static char *ev = "int";
79 #define WDT_TIMEOUT 60 /* 1 minute */
81 static bool nowayout = WATCHDOG_NOWAYOUT;
82 module_param(nowayout, bool, 0);
83 MODULE_PARM_DESC(nowayout,
84 "Watchdog cannot be stopped once started (default="
85 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
91 #define WDT_CTRL_REG 0x30
92 #define WDT_OUTPIN_CFG 0xe2
93 #define WDT_EVENT_INT 0x00
94 #define WDT_EVENT_REBOOT 0x08
95 #define WDT_UNIT_SEL 0xf1
96 #define WDT_UNIT_SECS 0x80
97 #define WDT_TIMEOUT_VAL 0xf2
98 #define WDT_TIMER_CFG 0xf3
101 module_param(io, int, 0);
102 MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
103 module_param(irq, int, 0);
104 MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
105 module_param(ev, charp, 0);
106 MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
110 * Programming support
113 static inline void eurwdt_write_reg(u8 index, u8 data)
119 static inline void eurwdt_lock_chip(void)
124 static inline void eurwdt_unlock_chip(void)
127 eurwdt_write_reg(0x07, 0x08); /* set the logical device */
130 static inline void eurwdt_set_timeout(int timeout)
132 eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
135 static inline void eurwdt_disable_timer(void)
137 eurwdt_set_timeout(0);
140 static void eurwdt_activate_timer(void)
142 eurwdt_disable_timer();
143 eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
144 eurwdt_write_reg(WDT_OUTPIN_CFG,
145 !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
147 /* Setting interrupt line */
148 if (irq == 2 || irq > 15 || irq < 0) {
149 pr_err("invalid irq number\n");
150 irq = 0; /* if invalid we disable interrupt */
153 pr_info("interrupt disabled\n");
155 eurwdt_write_reg(WDT_TIMER_CFG, irq << 4);
157 eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
158 eurwdt_set_timeout(0); /* the default timeout */
166 static irqreturn_t eurwdt_interrupt(int irq, void *dev_id)
168 pr_crit("timeout WDT timeout\n");
171 pr_crit("Would Reboot\n");
173 pr_crit("Initiating system reboot\n");
183 * Reload counter one with the watchdog timeout.
186 static void eurwdt_ping(void)
188 /* Write the watchdog default value */
189 eurwdt_set_timeout(eurwdt_timeout);
194 * @file: file handle to the watchdog
195 * @buf: buffer to write (unused as data does not matter here
196 * @count: count of bytes
197 * @ppos: pointer to the position to write. No seeks allowed
199 * A write to a watchdog device is defined as a keepalive signal. Any
200 * write of data will do, as we we don't define content meaning.
203 static ssize_t eurwdt_write(struct file *file, const char __user *buf,
204 size_t count, loff_t *ppos)
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 spin_lock(&eurwdt_lock);
221 eurwdt_ping(); /* the default timeout */
222 spin_unlock(&eurwdt_lock);
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 long eurwdt_ioctl(struct file *file,
238 unsigned int cmd, unsigned long arg)
240 void __user *argp = (void __user *)arg;
241 int __user *p = argp;
242 static const struct watchdog_info ident = {
243 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
245 .firmware_version = 1,
246 .identity = "WDT Eurotech CPU-1220/1410",
250 int options, retval = -EINVAL;
253 case WDIOC_GETSUPPORT:
254 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
256 case WDIOC_GETSTATUS:
257 case WDIOC_GETBOOTSTATUS:
258 return put_user(0, p);
260 case WDIOC_SETOPTIONS:
261 if (get_user(options, p))
263 spin_lock(&eurwdt_lock);
264 if (options & WDIOS_DISABLECARD) {
265 eurwdt_disable_timer();
268 if (options & WDIOS_ENABLECARD) {
269 eurwdt_activate_timer();
273 spin_unlock(&eurwdt_lock);
276 case WDIOC_KEEPALIVE:
277 spin_lock(&eurwdt_lock);
279 spin_unlock(&eurwdt_lock);
282 case WDIOC_SETTIMEOUT:
283 if (copy_from_user(&time, p, sizeof(int)))
287 if (time < 0 || time > 255)
290 spin_lock(&eurwdt_lock);
291 eurwdt_timeout = time;
292 eurwdt_set_timeout(time);
293 spin_unlock(&eurwdt_lock);
296 case WDIOC_GETTIMEOUT:
297 return put_user(eurwdt_timeout, p);
306 * @inode: inode of device
307 * @file: file handle to device
309 * The misc device has been opened. The watchdog device is single
310 * open and on opening we load the counter.
313 static int eurwdt_open(struct inode *inode, struct file *file)
315 if (test_and_set_bit(0, &eurwdt_is_open))
317 eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
318 /* Activate the WDT */
319 eurwdt_activate_timer();
320 return nonseekable_open(inode, file);
325 * @inode: inode to board
326 * @file: file handle to board
328 * The watchdog has a configurable API. There is a religious dispute
329 * between people who want their watchdog to be able to shut down and
330 * those who want to be sure if the watchdog manager dies the machine
331 * reboots. In the former case we disable the counters, in the latter
332 * case you have to open it again very soon.
335 static int eurwdt_release(struct inode *inode, struct file *file)
337 if (eur_expect_close == 42)
338 eurwdt_disable_timer();
340 pr_crit("Unexpected close, not stopping watchdog!\n");
343 clear_bit(0, &eurwdt_is_open);
344 eur_expect_close = 0;
350 * @this: our notifier block
351 * @code: the event being reported
354 * Our notifier is called on system shutdowns. We want to turn the card
355 * off at reboot otherwise the machine will reboot again during memory
356 * test or worse yet during the following fsck. This would suck, in fact
357 * trust me - if it happens it does suck.
360 static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
363 if (code == SYS_DOWN || code == SYS_HALT)
364 eurwdt_disable_timer(); /* Turn the card off */
374 static const struct file_operations eurwdt_fops = {
375 .owner = THIS_MODULE,
377 .write = eurwdt_write,
378 .unlocked_ioctl = eurwdt_ioctl,
380 .release = eurwdt_release,
383 static struct miscdevice eurwdt_miscdev = {
384 .minor = WATCHDOG_MINOR,
386 .fops = &eurwdt_fops,
390 * The WDT card needs to learn about soft shutdowns in order to
391 * turn the timebomb registers off.
394 static struct notifier_block eurwdt_notifier = {
395 .notifier_call = eurwdt_notify_sys,
401 * Unload the watchdog. You cannot do this with any file handles open.
402 * If your watchdog is set to continue ticking on close and you unload
403 * it, well it keeps ticking. We won't get the interrupt but the board
404 * will not touch PC memory so all is fine. You just have to load a new
405 * module in 60 seconds or reboot.
408 static void __exit eurwdt_exit(void)
412 misc_deregister(&eurwdt_miscdev);
414 unregister_reboot_notifier(&eurwdt_notifier);
415 release_region(io, 2);
422 * Set up the WDT watchdog board. After grabbing the resources
423 * we require we need also to unlock the device.
424 * The open() function will actually kick the board off.
427 static int __init eurwdt_init(void)
431 ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL);
433 pr_err("IRQ %d is not free\n", irq);
437 if (!request_region(io, 2, "eurwdt")) {
438 pr_err("IO %X is not free\n", io);
443 ret = register_reboot_notifier(&eurwdt_notifier);
445 pr_err("can't register reboot notifier (err=%d)\n", ret);
449 ret = misc_register(&eurwdt_miscdev);
451 pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR);
455 eurwdt_unlock_chip();
458 pr_info("Eurotech WDT driver 0.01 at %X (Interrupt %d) - timeout event: %s\n",
459 io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
465 unregister_reboot_notifier(&eurwdt_notifier);
468 release_region(io, 2);
475 module_init(eurwdt_init);
476 module_exit(eurwdt_exit);
478 MODULE_AUTHOR("Rodolfo Giometti");
479 MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
480 MODULE_LICENSE("GPL");
481 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);