2 * w83697hf/hg WDT driver
4 * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
5 * (c) Copyright 2006 Marcus Junker <junker@anduras.de>
7 * Based on w83627hf_wdt.c which is based on advantechwdt.c
8 * which is based on wdt.c.
9 * Original copyright messages:
11 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
13 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
15 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
16 * All Rights Reserved.
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
23 * Neither Marcus Junker nor ANDURAS AG admit liability nor provide
24 * warranty for any of this software. This material is provided
25 * "AS-IS" and at no charge.
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30 #include <linux/module.h>
31 #include <linux/moduleparam.h>
32 #include <linux/types.h>
33 #include <linux/miscdevice.h>
34 #include <linux/watchdog.h>
36 #include <linux/ioport.h>
37 #include <linux/notifier.h>
38 #include <linux/reboot.h>
39 #include <linux/init.h>
40 #include <linux/spinlock.h>
42 #include <linux/uaccess.h>
44 #include <asm/system.h>
46 #define WATCHDOG_NAME "w83697hf/hg WDT"
47 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
48 #define WATCHDOG_EARLY_DISABLE 1 /* Disable until userland kicks in */
50 static unsigned long wdt_is_open;
51 static char expect_close;
52 static DEFINE_SPINLOCK(io_lock);
54 /* You must set this - there is no sane way to probe for this board. */
55 static int wdt_io = 0x2e;
56 module_param(wdt_io, int, 0);
57 MODULE_PARM_DESC(wdt_io,
58 "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
60 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
61 module_param(timeout, int, 0);
62 MODULE_PARM_DESC(timeout,
63 "Watchdog timeout in seconds. 1<= timeout <=255 (default="
64 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
66 static bool nowayout = WATCHDOG_NOWAYOUT;
67 module_param(nowayout, bool, 0);
68 MODULE_PARM_DESC(nowayout,
69 "Watchdog cannot be stopped once started (default="
70 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72 static int early_disable = WATCHDOG_EARLY_DISABLE;
73 module_param(early_disable, int, 0);
74 MODULE_PARM_DESC(early_disable,
75 "Watchdog gets disabled at boot time (default="
76 __MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")");
82 #define W83697HF_EFER (wdt_io + 0) /* Extended Function Enable Register */
83 #define W83697HF_EFIR (wdt_io + 0) /* Extended Function Index Register
85 #define W83697HF_EFDR (wdt_io + 1) /* Extended Function Data Register */
87 static inline void w83697hf_unlock(void)
89 outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
90 outb_p(0x87, W83697HF_EFER); /* Again according to manual */
93 static inline void w83697hf_lock(void)
95 outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
99 * The three functions w83697hf_get_reg(), w83697hf_set_reg() and
100 * w83697hf_write_timeout() must be called with the device unlocked.
103 static unsigned char w83697hf_get_reg(unsigned char reg)
105 outb_p(reg, W83697HF_EFIR);
106 return inb_p(W83697HF_EFDR);
109 static void w83697hf_set_reg(unsigned char reg, unsigned char data)
111 outb_p(reg, W83697HF_EFIR);
112 outb_p(data, W83697HF_EFDR);
115 static void w83697hf_write_timeout(int timeout)
117 /* Write Timeout counter to CRF4 */
118 w83697hf_set_reg(0xF4, timeout);
121 static void w83697hf_select_wdt(void)
124 w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
127 static inline void w83697hf_deselect_wdt(void)
132 static void w83697hf_init(void)
136 w83697hf_select_wdt();
138 bbuf = w83697hf_get_reg(0x29);
142 /* Set pin 119 to WDTO# mode (= CR29, WDT0) */
143 w83697hf_set_reg(0x29, bbuf);
145 bbuf = w83697hf_get_reg(0xF3);
147 w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
149 w83697hf_deselect_wdt();
152 static void wdt_ping(void)
155 w83697hf_select_wdt();
157 w83697hf_write_timeout(timeout);
159 w83697hf_deselect_wdt();
160 spin_unlock(&io_lock);
163 static void wdt_enable(void)
166 w83697hf_select_wdt();
168 w83697hf_write_timeout(timeout);
169 w83697hf_set_reg(0x30, 1); /* Enable timer */
171 w83697hf_deselect_wdt();
172 spin_unlock(&io_lock);
175 static void wdt_disable(void)
178 w83697hf_select_wdt();
180 w83697hf_set_reg(0x30, 0); /* Disable timer */
181 w83697hf_write_timeout(0);
183 w83697hf_deselect_wdt();
184 spin_unlock(&io_lock);
187 static unsigned char wdt_running(void)
192 w83697hf_select_wdt();
194 t = w83697hf_get_reg(0xF4); /* Read timer */
196 w83697hf_deselect_wdt();
197 spin_unlock(&io_lock);
202 static int wdt_set_heartbeat(int t)
204 if (t < 1 || t > 255)
211 static ssize_t wdt_write(struct file *file, const char __user *buf,
212 size_t count, loff_t *ppos)
220 for (i = 0; i != count; i++) {
222 if (get_user(c, buf + i))
233 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
235 void __user *argp = (void __user *)arg;
236 int __user *p = argp;
238 static const struct watchdog_info ident = {
239 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
241 .firmware_version = 1,
242 .identity = "W83697HF WDT",
246 case WDIOC_GETSUPPORT:
247 if (copy_to_user(argp, &ident, sizeof(ident)))
251 case WDIOC_GETSTATUS:
252 case WDIOC_GETBOOTSTATUS:
253 return put_user(0, p);
255 case WDIOC_SETOPTIONS:
257 int options, retval = -EINVAL;
259 if (get_user(options, p))
262 if (options & WDIOS_DISABLECARD) {
267 if (options & WDIOS_ENABLECARD) {
275 case WDIOC_KEEPALIVE:
279 case WDIOC_SETTIMEOUT:
280 if (get_user(new_timeout, p))
282 if (wdt_set_heartbeat(new_timeout))
287 case WDIOC_GETTIMEOUT:
288 return put_user(timeout, p);
296 static int wdt_open(struct inode *inode, struct file *file)
298 if (test_and_set_bit(0, &wdt_is_open))
305 return nonseekable_open(inode, file);
308 static int wdt_close(struct inode *inode, struct file *file)
310 if (expect_close == 42)
313 pr_crit("Unexpected close, not stopping watchdog!\n");
317 clear_bit(0, &wdt_is_open);
322 * Notifier for system down
325 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
328 if (code == SYS_DOWN || code == SYS_HALT)
329 wdt_disable(); /* Turn the WDT off */
338 static const struct file_operations wdt_fops = {
339 .owner = THIS_MODULE,
342 .unlocked_ioctl = wdt_ioctl,
344 .release = wdt_close,
347 static struct miscdevice wdt_miscdev = {
348 .minor = WATCHDOG_MINOR,
354 * The WDT needs to learn about soft shutdowns in order to
355 * turn the timebomb registers off.
358 static struct notifier_block wdt_notifier = {
359 .notifier_call = wdt_notify_sys,
362 static int w83697hf_check_wdt(void)
364 if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
365 pr_err("I/O address 0x%x already in use\n", wdt_io);
369 pr_debug("Looking for watchdog at address 0x%x\n", wdt_io);
371 if (w83697hf_get_reg(0x20) == 0x60) {
372 pr_info("watchdog found at address 0x%x\n", wdt_io);
376 /* Reprotect in case it was a compatible device */
379 pr_info("watchdog not found at address 0x%x\n", wdt_io);
380 release_region(wdt_io, 2);
384 static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
386 static int __init wdt_init(void)
388 int ret, i, found = 0;
390 pr_info("WDT driver for W83697HF/HG initializing\n");
393 /* we will autodetect the W83697HF/HG watchdog */
394 for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
395 wdt_io = w83697hf_ioports[i];
396 if (!w83697hf_check_wdt())
400 if (!w83697hf_check_wdt())
405 pr_err("No W83697HF/HG could be found\n");
413 pr_warn("Stopping previously enabled watchdog until userland kicks in\n");
417 if (wdt_set_heartbeat(timeout)) {
418 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
419 pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
423 ret = register_reboot_notifier(&wdt_notifier);
425 pr_err("cannot register reboot notifier (err=%d)\n", ret);
429 ret = misc_register(&wdt_miscdev);
431 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
432 WATCHDOG_MINOR, ret);
436 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
442 unregister_reboot_notifier(&wdt_notifier);
444 release_region(wdt_io, 2);
448 static void __exit wdt_exit(void)
450 misc_deregister(&wdt_miscdev);
451 unregister_reboot_notifier(&wdt_notifier);
452 release_region(wdt_io, 2);
455 module_init(wdt_init);
456 module_exit(wdt_exit);
458 MODULE_LICENSE("GPL");
459 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, "
460 "Samuel Tardieu <sam@rfc1149.net>");
461 MODULE_DESCRIPTION("w83697hf/hg WDT driver");
462 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);