1/*
2 *	w83627hf/thf WDT driver
3 *
4 *	(c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
5 *		added support for W83627THF.
6 *
7 *	(c) Copyright 2003 P�draig Brady <P@draigBrady.com>
8 *
9 *	Based on advantechwdt.c which is based on wdt.c.
10 *	Original copyright messages:
11 *
12 *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
13 *
14 *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
15 *				http://www.redhat.com
16 *
17 *	This program is free software; you can redistribute it and/or
18 *	modify it under the terms of the GNU General Public License
19 *	as published by the Free Software Foundation; either version
20 *	2 of the License, or (at your option) any later version.
21 *
22 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
23 *	warranty for any of this software. This material is provided
24 *	"AS-IS" and at no charge.
25 *
26 *	(c) Copyright 1995    Alan Cox <alan@redhat.com>
27 */
28
29#include <linux/module.h>
30#include <linux/moduleparam.h>
31#include <linux/types.h>
32#include <linux/miscdevice.h>
33#include <linux/watchdog.h>
34#include <linux/fs.h>
35#include <linux/ioport.h>
36#include <linux/notifier.h>
37#include <linux/reboot.h>
38#include <linux/init.h>
39#include <linux/spinlock.h>
40
41#include <asm/io.h>
42#include <asm/uaccess.h>
43#include <asm/system.h>
44
45#define WATCHDOG_NAME "w83627hf/thf WDT"
46#define PFX WATCHDOG_NAME ": "
47#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
48
49static unsigned long wdt_is_open;
50static char expect_close;
51static spinlock_t io_lock;
52
53/* You must set this - there is no sane way to probe for this board. */
54static int wdt_io = 0x2E;
55module_param(wdt_io, int, 0);
56MODULE_PARM_DESC(wdt_io, "w83627hf/thf WDT io port (default 0x2E)");
57
58static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
59module_param(timeout, int, 0);
60MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
61
62static int nowayout = WATCHDOG_NOWAYOUT;
63module_param(nowayout, int, 0);
64MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
65
66/*
67 *	Kernel methods.
68 */
69
70#define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
71#define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register (same as EFER) */
72#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
73
74static void
75w83627hf_select_wd_register(void)
76{
77	unsigned char c;
78	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
79	outb_p(0x87, WDT_EFER); /* Again according to manual */
80
81	outb(0x20, WDT_EFER); 	/* check chip version	*/
82	c = inb(WDT_EFDR);
83	if (c == 0x82) {	/* W83627THF 		*/
84		outb_p(0x2b, WDT_EFER); /* select GPIO3 */
85		c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
86		outb_p(0x2b, WDT_EFER);
87		outb_p(c, WDT_EFDR);	/* set GPIO3 to WDT0 */
88	}
89
90	outb_p(0x07, WDT_EFER); /* point to logical device number reg */
91	outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
92	outb_p(0x30, WDT_EFER); /* select CR30 */
93	outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
94}
95
96static void
97w83627hf_unselect_wd_register(void)
98{
99	outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
100}
101
102/* tyan motherboards seem to set F5 to 0x4C ?
103 * So explicitly init to appropriate value. */
104static void
105w83627hf_init(void)
106{
107	unsigned char t;
108
109	w83627hf_select_wd_register();
110
111	outb_p(0xF6, WDT_EFER); /* Select CRF6 */
112	t=inb_p(WDT_EFDR);      /* read CRF6 */
113	if (t != 0) {
114		printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
115		outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
116	}
117	outb_p(0xF5, WDT_EFER); /* Select CRF5 */
118	t=inb_p(WDT_EFDR);      /* read CRF5 */
119	t&=~0x0C;               /* set second mode & disable keyboard turning off watchdog */
120	outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
121
122	w83627hf_unselect_wd_register();
123}
124
125static void
126wdt_ctrl(int timeout)
127{
128	spin_lock(&io_lock);
129
130	w83627hf_select_wd_register();
131
132	outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
133	outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
134
135	w83627hf_unselect_wd_register();
136
137	spin_unlock(&io_lock);
138}
139
140static int
141wdt_ping(void)
142{
143	wdt_ctrl(timeout);
144	return 0;
145}
146
147static int
148wdt_disable(void)
149{
150	wdt_ctrl(0);
151	return 0;
152}
153
154static int
155wdt_set_heartbeat(int t)
156{
157	if ((t < 1) || (t > 63))
158		return -EINVAL;
159
160	timeout = t;
161	return 0;
162}
163
164static ssize_t
165wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
166{
167	if (count) {
168		if (!nowayout) {
169			size_t i;
170
171			expect_close = 0;
172
173			for (i = 0; i != count; i++) {
174				char c;
175				if (get_user(c, buf+i))
176					return -EFAULT;
177				if (c == 'V')
178					expect_close = 42;
179			}
180		}
181		wdt_ping();
182	}
183	return count;
184}
185
186static int
187wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
188	  unsigned long arg)
189{
190	void __user *argp = (void __user *)arg;
191	int __user *p = argp;
192	int new_timeout;
193	static struct watchdog_info ident = {
194		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
195		.firmware_version = 1,
196		.identity = "W83627HF WDT",
197	};
198
199	switch (cmd) {
200	case WDIOC_GETSUPPORT:
201	  if (copy_to_user(argp, &ident, sizeof(ident)))
202	    return -EFAULT;
203	  break;
204
205	case WDIOC_GETSTATUS:
206	case WDIOC_GETBOOTSTATUS:
207	  return put_user(0, p);
208
209	case WDIOC_KEEPALIVE:
210	  wdt_ping();
211	  break;
212
213	case WDIOC_SETTIMEOUT:
214	  if (get_user(new_timeout, p))
215		  return -EFAULT;
216	  if (wdt_set_heartbeat(new_timeout))
217		  return -EINVAL;
218	  wdt_ping();
219	  /* Fall */
220
221	case WDIOC_GETTIMEOUT:
222	  return put_user(timeout, p);
223
224	case WDIOC_SETOPTIONS:
225	{
226	  int options, retval = -EINVAL;
227
228	  if (get_user(options, p))
229	    return -EFAULT;
230
231	  if (options & WDIOS_DISABLECARD) {
232	    wdt_disable();
233	    retval = 0;
234	  }
235
236	  if (options & WDIOS_ENABLECARD) {
237	    wdt_ping();
238	    retval = 0;
239	  }
240
241	  return retval;
242	}
243
244	default:
245	  return -ENOTTY;
246	}
247	return 0;
248}
249
250static int
251wdt_open(struct inode *inode, struct file *file)
252{
253	if (test_and_set_bit(0, &wdt_is_open))
254		return -EBUSY;
255	/*
256	 *	Activate
257	 */
258
259	wdt_ping();
260	return nonseekable_open(inode, file);
261}
262
263static int
264wdt_close(struct inode *inode, struct file *file)
265{
266	if (expect_close == 42) {
267		wdt_disable();
268	} else {
269		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
270		wdt_ping();
271	}
272	expect_close = 0;
273	clear_bit(0, &wdt_is_open);
274	return 0;
275}
276
277/*
278 *	Notifier for system down
279 */
280
281static int
282wdt_notify_sys(struct notifier_block *this, unsigned long code,
283	void *unused)
284{
285	if (code == SYS_DOWN || code == SYS_HALT) {
286		/* Turn the WDT off */
287		wdt_disable();
288	}
289	return NOTIFY_DONE;
290}
291
292/*
293 *	Kernel Interfaces
294 */
295
296static const struct file_operations wdt_fops = {
297	.owner		= THIS_MODULE,
298	.llseek		= no_llseek,
299	.write		= wdt_write,
300	.ioctl		= wdt_ioctl,
301	.open		= wdt_open,
302	.release	= wdt_close,
303};
304
305static struct miscdevice wdt_miscdev = {
306	.minor = WATCHDOG_MINOR,
307	.name = "watchdog",
308	.fops = &wdt_fops,
309};
310
311/*
312 *	The WDT needs to learn about soft shutdowns in order to
313 *	turn the timebomb registers off.
314 */
315
316static struct notifier_block wdt_notifier = {
317	.notifier_call = wdt_notify_sys,
318};
319
320static int __init
321wdt_init(void)
322{
323	int ret;
324
325	spin_lock_init(&io_lock);
326
327	printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF Super I/O chip initialising.\n");
328
329	if (wdt_set_heartbeat(timeout)) {
330		wdt_set_heartbeat(WATCHDOG_TIMEOUT);
331		printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
332			WATCHDOG_TIMEOUT);
333	}
334
335	if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
336		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
337			wdt_io);
338		ret = -EIO;
339		goto out;
340	}
341
342	w83627hf_init();
343
344	ret = register_reboot_notifier(&wdt_notifier);
345	if (ret != 0) {
346		printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
347			ret);
348		goto unreg_regions;
349	}
350
351	ret = misc_register(&wdt_miscdev);
352	if (ret != 0) {
353		printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
354			WATCHDOG_MINOR, ret);
355		goto unreg_reboot;
356	}
357
358	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
359		timeout, nowayout);
360
361out:
362	return ret;
363unreg_reboot:
364	unregister_reboot_notifier(&wdt_notifier);
365unreg_regions:
366	release_region(wdt_io, 1);
367	goto out;
368}
369
370static void __exit
371wdt_exit(void)
372{
373	misc_deregister(&wdt_miscdev);
374	unregister_reboot_notifier(&wdt_notifier);
375	release_region(wdt_io,1);
376}
377
378module_init(wdt_init);
379module_exit(wdt_exit);
380
381MODULE_LICENSE("GPL");
382MODULE_AUTHOR("P�draig Brady <P@draigBrady.com>");
383MODULE_DESCRIPTION("w83627hf/thf WDT driver");
384MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
385