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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>
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +00005 * reused original code to support w83697ug/uf.
Flemming Frandsen7d8b0902008-04-17 11:29:54 +02006 *
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
Joe Perches27c766a2012-02-15 15:06:19 -080033#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020035#include <linux/module.h>
36#include <linux/moduleparam.h>
37#include <linux/types.h>
38#include <linux/miscdevice.h>
39#include <linux/watchdog.h>
40#include <linux/fs.h>
41#include <linux/ioport.h>
42#include <linux/notifier.h>
43#include <linux/reboot.h>
44#include <linux/init.h>
45#include <linux/spinlock.h>
46#include <linux/io.h>
47#include <linux/uaccess.h>
48
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020049
50#define WATCHDOG_NAME "w83697ug/uf WDT"
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020051#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
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010067static bool nowayout = WATCHDOG_NOWAYOUT;
68module_param(nowayout, bool, 0);
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020069MODULE_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
Eric Lammerts63bad142009-02-03 17:45:56 -050082static int w83697ug_select_wd_register(void)
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020083{
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
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +000090 outb(0x20, WDT_EFER); /* check chip version */
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020091 version = inb(WDT_EFDR);
92
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +000093 if (version == 0x68) { /* W83697UG */
Joe Perches27c766a2012-02-15 15:06:19 -080094 pr_info("Watchdog chip version 0x%02x = W83697UG/UF found at 0x%04x\n",
95 version, wdt_io);
Flemming Frandsen7d8b0902008-04-17 11:29:54 +020096
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 {
Joe Perches27c766a2012-02-15 15:06:19 -0800104 pr_err("No W83697UG/UF could be found\n");
Eric Lammerts63bad142009-02-03 17:45:56 -0500105 return -ENODEV;
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);
Wim Van Sebroeck943413c2011-02-21 19:28:58 +0000112 outb_p(c | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
Eric Lammerts63bad142009-02-03 17:45:56 -0500113
114 return 0;
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200115}
116
117static void w83697ug_unselect_wd_register(void)
118{
119 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
120}
121
Eric Lammerts63bad142009-02-03 17:45:56 -0500122static int w83697ug_init(void)
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200123{
Eric Lammerts63bad142009-02-03 17:45:56 -0500124 int ret;
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200125 unsigned char t;
126
Eric Lammerts63bad142009-02-03 17:45:56 -0500127 ret = w83697ug_select_wd_register();
128 if (ret != 0)
129 return ret;
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200130
131 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
132 t = inb_p(WDT_EFDR); /* read CRF6 */
133 if (t != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800134 pr_info("Watchdog already running. Resetting timeout to %d sec\n",
135 timeout);
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200136 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
137 }
138 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
139 t = inb_p(WDT_EFDR); /* read CRF5 */
140 t &= ~0x0C; /* set second mode &
141 disable keyboard turning off watchdog */
142 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
143
144 w83697ug_unselect_wd_register();
Eric Lammerts63bad142009-02-03 17:45:56 -0500145 return 0;
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200146}
147
148static void wdt_ctrl(int timeout)
149{
150 spin_lock(&io_lock);
151
Jiri Slabydb5d2d82009-06-29 18:00:39 +0200152 if (w83697ug_select_wd_register() < 0) {
153 spin_unlock(&io_lock);
Eric Lammerts63bad142009-02-03 17:45:56 -0500154 return;
Jiri Slabydb5d2d82009-06-29 18:00:39 +0200155 }
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200156
157 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
158 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
159
160 w83697ug_unselect_wd_register();
161
162 spin_unlock(&io_lock);
163}
164
165static int wdt_ping(void)
166{
167 wdt_ctrl(timeout);
168 return 0;
169}
170
171static int wdt_disable(void)
172{
173 wdt_ctrl(0);
174 return 0;
175}
176
177static int wdt_set_heartbeat(int t)
178{
179 if (t < 1 || t > 255)
180 return -EINVAL;
181
182 timeout = t;
183 return 0;
184}
185
186static ssize_t wdt_write(struct file *file, const char __user *buf,
187 size_t count, loff_t *ppos)
188{
189 if (count) {
190 if (!nowayout) {
191 size_t i;
192
193 expect_close = 0;
194
195 for (i = 0; i != count; i++) {
196 char c;
197 if (get_user(c, buf + i))
198 return -EFAULT;
199 if (c == 'V')
200 expect_close = 42;
201 }
202 }
203 wdt_ping();
204 }
205 return count;
206}
207
208static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
209{
210 void __user *argp = (void __user *)arg;
211 int __user *p = argp;
212 int new_timeout;
213 static const struct watchdog_info ident = {
214 .options = WDIOF_KEEPALIVEPING |
215 WDIOF_SETTIMEOUT |
216 WDIOF_MAGICCLOSE,
217 .firmware_version = 1,
218 .identity = "W83697UG WDT",
219 };
220
221 switch (cmd) {
222 case WDIOC_GETSUPPORT:
223 if (copy_to_user(argp, &ident, sizeof(ident)))
224 return -EFAULT;
225 break;
226
227 case WDIOC_GETSTATUS:
228 case WDIOC_GETBOOTSTATUS:
229 return put_user(0, p);
230
231 case WDIOC_SETOPTIONS:
232 {
233 int options, retval = -EINVAL;
234
235 if (get_user(options, p))
236 return -EFAULT;
237
238 if (options & WDIOS_DISABLECARD) {
239 wdt_disable();
240 retval = 0;
241 }
242
243 if (options & WDIOS_ENABLECARD) {
244 wdt_ping();
245 retval = 0;
246 }
247
248 return retval;
249 }
250
251 case WDIOC_KEEPALIVE:
252 wdt_ping();
253 break;
254
255 case WDIOC_SETTIMEOUT:
256 if (get_user(new_timeout, p))
257 return -EFAULT;
258 if (wdt_set_heartbeat(new_timeout))
259 return -EINVAL;
260 wdt_ping();
261 /* Fall */
262
263 case WDIOC_GETTIMEOUT:
264 return put_user(timeout, p);
265
266 default:
267 return -ENOTTY;
268 }
269 return 0;
270}
271
272static int wdt_open(struct inode *inode, struct file *file)
273{
274 if (test_and_set_bit(0, &wdt_is_open))
275 return -EBUSY;
276 /*
277 * Activate
278 */
279
280 wdt_ping();
281 return nonseekable_open(inode, file);
282}
283
284static int wdt_close(struct inode *inode, struct file *file)
285{
286 if (expect_close == 42)
287 wdt_disable();
288 else {
Joe Perches27c766a2012-02-15 15:06:19 -0800289 pr_crit("Unexpected close, not stopping watchdog!\n");
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200290 wdt_ping();
291 }
292 expect_close = 0;
293 clear_bit(0, &wdt_is_open);
294 return 0;
295}
296
297/*
298 * Notifier for system down
299 */
300
301static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
302 void *unused)
303{
304 if (code == SYS_DOWN || code == SYS_HALT)
305 wdt_disable(); /* Turn the WDT off */
306
307 return NOTIFY_DONE;
308}
309
310/*
311 * Kernel Interfaces
312 */
313
314static const struct file_operations wdt_fops = {
315 .owner = THIS_MODULE,
316 .llseek = no_llseek,
317 .write = wdt_write,
318 .unlocked_ioctl = wdt_ioctl,
319 .open = wdt_open,
320 .release = wdt_close,
321};
322
323static struct miscdevice wdt_miscdev = {
324 .minor = WATCHDOG_MINOR,
325 .name = "watchdog",
326 .fops = &wdt_fops,
327};
328
329/*
330 * The WDT needs to learn about soft shutdowns in order to
331 * turn the timebomb registers off.
332 */
333
334static struct notifier_block wdt_notifier = {
335 .notifier_call = wdt_notify_sys,
336};
337
338static int __init wdt_init(void)
339{
340 int ret;
341
Joe Perches27c766a2012-02-15 15:06:19 -0800342 pr_info("WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising\n");
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200343
344 if (wdt_set_heartbeat(timeout)) {
345 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
Joe Perches27c766a2012-02-15 15:06:19 -0800346 pr_info("timeout value must be 1<=timeout<=255, using %d\n",
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200347 WATCHDOG_TIMEOUT);
348 }
349
350 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800351 pr_err("I/O address 0x%04x already in use\n", wdt_io);
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200352 ret = -EIO;
353 goto out;
354 }
355
Eric Lammerts63bad142009-02-03 17:45:56 -0500356 ret = w83697ug_init();
357 if (ret != 0)
358 goto unreg_regions;
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200359
360 ret = register_reboot_notifier(&wdt_notifier);
361 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800362 pr_err("cannot register reboot notifier (err=%d)\n", ret);
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200363 goto unreg_regions;
364 }
365
366 ret = misc_register(&wdt_miscdev);
367 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800368 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
369 WATCHDOG_MINOR, ret);
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200370 goto unreg_reboot;
371 }
372
Joe Perches27c766a2012-02-15 15:06:19 -0800373 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
Flemming Frandsen7d8b0902008-04-17 11:29:54 +0200374 timeout, nowayout);
375
376out:
377 return ret;
378unreg_reboot:
379 unregister_reboot_notifier(&wdt_notifier);
380unreg_regions:
381 release_region(wdt_io, 1);
382 goto out;
383}
384
385static void __exit wdt_exit(void)
386{
387 misc_deregister(&wdt_miscdev);
388 unregister_reboot_notifier(&wdt_notifier);
389 release_region(wdt_io, 1);
390}
391
392module_init(wdt_init);
393module_exit(wdt_exit);
394
395MODULE_LICENSE("GPL");
396MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
397MODULE_DESCRIPTION("w83697ug/uf WDT driver");
398MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);