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Flemming Frandsen7d8b0902008-04-17 11:29:54 +02001/*
2 * w83697ug/uf WDT driver
3 *
4 * (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
5 * reused original code to supoprt w83697ug/uf.
6 *
7 * Based on w83627hf_wdt.c which is based on advantechwdt.c
8 * which is based on wdt.c.
9 * Original copyright messages:
10 *
11 * (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
12 * added support for W83627THF.
13 *
14 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
15 *
16 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
17 *
18 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
19 * http://www.redhat.com
20 *
21 * This program is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU General Public License
23 * as published by the Free Software Foundation; either version
24 * 2 of the License, or (at your option) any later version.
25 *
26 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
27 * warranty for any of this software. This material is provided
28 * "AS-IS" and at no charge.
29 *
30 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
31 */
32
33#include <linux/module.h>
34#include <linux/moduleparam.h>
35#include <linux/types.h>
36#include <linux/miscdevice.h>
37#include <linux/watchdog.h>
38#include <linux/fs.h>
39#include <linux/ioport.h>
40#include <linux/notifier.h>
41#include <linux/reboot.h>
42#include <linux/init.h>
43#include <linux/spinlock.h>
44#include <linux/io.h>
45#include <linux/uaccess.h>
46
47#include <asm/system.h>
48
49#define WATCHDOG_NAME "w83697ug/uf WDT"
50#define PFX WATCHDOG_NAME ": "
51#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
52
53static unsigned long wdt_is_open;
54static char expect_close;
55static DEFINE_SPINLOCK(io_lock);
56
57static int wdt_io = 0x2e;
58module_param(wdt_io, int, 0);
59MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
60
61static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
62module_param(timeout, int, 0);
63MODULE_PARM_DESC(timeout,
64 "Watchdog timeout in seconds. 1<= timeout <=255 (default="
65 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
66
67static int nowayout = WATCHDOG_NOWAYOUT;
68module_param(nowayout, int, 0);
69MODULE_PARM_DESC(nowayout,
70 "Watchdog cannot be stopped once started (default="
71 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72
73/*
74 * Kernel methods.
75 */
76
77#define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
78#define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
79 (same as EFER) */
80#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
81
82static void w83697ug_select_wd_register(void)
83{
84 unsigned char c;
85 unsigned char version;
86
87 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
88 outb_p(0x87, WDT_EFER); /* Again according to manual */
89
90 outb(0x20, WDT_EFER); /* check chip version */
91 version = inb(WDT_EFDR);
92
93 if (version == 0x68) { /* W83697UG */
94 printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
95 "W83697UG/UF found at 0x%04x\n", version, wdt_io);
96
97 outb_p(0x2b, WDT_EFER);
98 c = inb_p(WDT_EFDR); /* select WDT0 */
99 c &= ~0x04;
100 outb_p(0x2b, WDT_EFER);
101 outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */
102
103 } else {
104 printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
Alan Cox7dc9b482008-10-21 13:44:58 +0100105 return;
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200106 }
107
108 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
109 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
110 outb_p(0x30, WDT_EFER); /* select CR30 */
111 c = inb_p(WDT_EFDR);
112 outb_p(c || 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
113}
114
115static void w83697ug_unselect_wd_register(void)
116{
117 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
118}
119
120static void w83697ug_init(void)
121{
122 unsigned char t;
123
124 w83697ug_select_wd_register();
125
126 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
127 t = inb_p(WDT_EFDR); /* read CRF6 */
128 if (t != 0) {
129 printk(KERN_INFO PFX "Watchdog already running."
130 " Resetting timeout to %d sec\n", timeout);
131 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
132 }
133 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
134 t = inb_p(WDT_EFDR); /* read CRF5 */
135 t &= ~0x0C; /* set second mode &
136 disable keyboard turning off watchdog */
137 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
138
139 w83697ug_unselect_wd_register();
140}
141
142static void wdt_ctrl(int timeout)
143{
144 spin_lock(&io_lock);
145
146 w83697ug_select_wd_register();
147
148 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
149 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
150
151 w83697ug_unselect_wd_register();
152
153 spin_unlock(&io_lock);
154}
155
156static int wdt_ping(void)
157{
158 wdt_ctrl(timeout);
159 return 0;
160}
161
162static int wdt_disable(void)
163{
164 wdt_ctrl(0);
165 return 0;
166}
167
168static int wdt_set_heartbeat(int t)
169{
170 if (t < 1 || t > 255)
171 return -EINVAL;
172
173 timeout = t;
174 return 0;
175}
176
177static ssize_t wdt_write(struct file *file, const char __user *buf,
178 size_t count, loff_t *ppos)
179{
180 if (count) {
181 if (!nowayout) {
182 size_t i;
183
184 expect_close = 0;
185
186 for (i = 0; i != count; i++) {
187 char c;
188 if (get_user(c, buf + i))
189 return -EFAULT;
190 if (c == 'V')
191 expect_close = 42;
192 }
193 }
194 wdt_ping();
195 }
196 return count;
197}
198
199static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
200{
201 void __user *argp = (void __user *)arg;
202 int __user *p = argp;
203 int new_timeout;
204 static const struct watchdog_info ident = {
205 .options = WDIOF_KEEPALIVEPING |
206 WDIOF_SETTIMEOUT |
207 WDIOF_MAGICCLOSE,
208 .firmware_version = 1,
209 .identity = "W83697UG WDT",
210 };
211
212 switch (cmd) {
213 case WDIOC_GETSUPPORT:
214 if (copy_to_user(argp, &ident, sizeof(ident)))
215 return -EFAULT;
216 break;
217
218 case WDIOC_GETSTATUS:
219 case WDIOC_GETBOOTSTATUS:
220 return put_user(0, p);
221
222 case WDIOC_SETOPTIONS:
223 {
224 int options, retval = -EINVAL;
225
226 if (get_user(options, p))
227 return -EFAULT;
228
229 if (options & WDIOS_DISABLECARD) {
230 wdt_disable();
231 retval = 0;
232 }
233
234 if (options & WDIOS_ENABLECARD) {
235 wdt_ping();
236 retval = 0;
237 }
238
239 return retval;
240 }
241
242 case WDIOC_KEEPALIVE:
243 wdt_ping();
244 break;
245
246 case WDIOC_SETTIMEOUT:
247 if (get_user(new_timeout, p))
248 return -EFAULT;
249 if (wdt_set_heartbeat(new_timeout))
250 return -EINVAL;
251 wdt_ping();
252 /* Fall */
253
254 case WDIOC_GETTIMEOUT:
255 return put_user(timeout, p);
256
257 default:
258 return -ENOTTY;
259 }
260 return 0;
261}
262
263static int wdt_open(struct inode *inode, struct file *file)
264{
265 if (test_and_set_bit(0, &wdt_is_open))
266 return -EBUSY;
267 /*
268 * Activate
269 */
270
271 wdt_ping();
272 return nonseekable_open(inode, file);
273}
274
275static int wdt_close(struct inode *inode, struct file *file)
276{
277 if (expect_close == 42)
278 wdt_disable();
279 else {
280 printk(KERN_CRIT PFX
281 "Unexpected close, not stopping watchdog!\n");
282 wdt_ping();
283 }
284 expect_close = 0;
285 clear_bit(0, &wdt_is_open);
286 return 0;
287}
288
289/*
290 * Notifier for system down
291 */
292
293static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
294 void *unused)
295{
296 if (code == SYS_DOWN || code == SYS_HALT)
297 wdt_disable(); /* Turn the WDT off */
298
299 return NOTIFY_DONE;
300}
301
302/*
303 * Kernel Interfaces
304 */
305
306static const struct file_operations wdt_fops = {
307 .owner = THIS_MODULE,
308 .llseek = no_llseek,
309 .write = wdt_write,
310 .unlocked_ioctl = wdt_ioctl,
311 .open = wdt_open,
312 .release = wdt_close,
313};
314
315static struct miscdevice wdt_miscdev = {
316 .minor = WATCHDOG_MINOR,
317 .name = "watchdog",
318 .fops = &wdt_fops,
319};
320
321/*
322 * The WDT needs to learn about soft shutdowns in order to
323 * turn the timebomb registers off.
324 */
325
326static struct notifier_block wdt_notifier = {
327 .notifier_call = wdt_notify_sys,
328};
329
330static int __init wdt_init(void)
331{
332 int ret;
333
334 printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");
335
336 if (wdt_set_heartbeat(timeout)) {
337 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
338 printk(KERN_INFO PFX
339 "timeout value must be 1<=timeout<=255, using %d\n",
340 WATCHDOG_TIMEOUT);
341 }
342
343 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
344 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
345 wdt_io);
346 ret = -EIO;
347 goto out;
348 }
349
350 w83697ug_init();
351
352 ret = register_reboot_notifier(&wdt_notifier);
353 if (ret != 0) {
354 printk(KERN_ERR PFX
355 "cannot register reboot notifier (err=%d)\n", ret);
356 goto unreg_regions;
357 }
358
359 ret = misc_register(&wdt_miscdev);
360 if (ret != 0) {
361 printk(KERN_ERR PFX
362 "cannot register miscdev on minor=%d (err=%d)\n",
363 WATCHDOG_MINOR, ret);
364 goto unreg_reboot;
365 }
366
367 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
368 timeout, nowayout);
369
370out:
371 return ret;
372unreg_reboot:
373 unregister_reboot_notifier(&wdt_notifier);
374unreg_regions:
375 release_region(wdt_io, 1);
376 goto out;
377}
378
379static void __exit wdt_exit(void)
380{
381 misc_deregister(&wdt_miscdev);
382 unregister_reboot_notifier(&wdt_notifier);
383 release_region(wdt_io, 1);
384}
385
386module_init(wdt_init);
387module_exit(wdt_exit);
388
389MODULE_LICENSE("GPL");
390MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
391MODULE_DESCRIPTION("w83697ug/uf WDT driver");
392MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);