aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/mixcomwd.c
blob: 1adf1d56027df58081b737201ddf860c420ce6fe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
/*
 * MixCom Watchdog: A Simple Hardware Watchdog Device
 * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
 *
 * Author: Gergely Madarasz <gorgo@itc.hu>
 *
 * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * Version 0.1 (99/04/15):
 *		- first version
 *
 * Version 0.2 (99/06/16):
 *		- added kernel timer watchdog ping after close
 *		  since the hardware does not support watchdog shutdown
 *
 * Version 0.3 (99/06/21):
 *		- added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
 *
 * Version 0.3.1 (99/06/22):
 *		- allow module removal while internal timer is active,
 *		  print warning about probable reset
 *
 * Version 0.4 (99/11/15):
 *		- support for one more type board
 *
 * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
 *		- added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *
 * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
 *		- make mixcomwd_opened unsigned,
 *		  removed lock_kernel/unlock_kernel from mixcomwd_release,
 *		  modified ioctl a bit to conform to API
 *
 */

#define VERSION "0.6"
#define WATCHDOG_NAME "mixcomwd"
#define PFX WATCHDOG_NAME ": "

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/*
 * We have two types of cards that can be probed:
 * 1) The Mixcom cards: these cards can be found at addresses
 *    0x180, 0x280, 0x380 with an additional offset of 0xc10.
 *    (Or 0xd90, 0xe90, 0xf90).
 * 2) The FlashCOM cards: these cards can be set up at
 *    0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
 *    (Or 0x304 -> 0x37c in 0x8 jumps).
 *    Each card has it's own ID.
 */
#define MIXCOM_ID 0x11
#define FLASHCOM_ID 0x18
static struct {
	int ioport;
	int id;
} mixcomwd_io_info[] __devinitdata = {
	/* The Mixcom cards */
	{0x0d90, MIXCOM_ID},
	{0x0e90, MIXCOM_ID},
	{0x0f90, MIXCOM_ID},
	/* The FlashCOM cards */
	{0x0304, FLASHCOM_ID},
	{0x030c, FLASHCOM_ID},
	{0x0314, FLASHCOM_ID},
	{0x031c, FLASHCOM_ID},
	{0x0324, FLASHCOM_ID},
	{0x032c, FLASHCOM_ID},
	{0x0334, FLASHCOM_ID},
	{0x033c, FLASHCOM_ID},
	{0x0344, FLASHCOM_ID},
	{0x034c, FLASHCOM_ID},
	{0x0354, FLASHCOM_ID},
	{0x035c, FLASHCOM_ID},
	{0x0364, FLASHCOM_ID},
	{0x036c, FLASHCOM_ID},
	{0x0374, FLASHCOM_ID},
	{0x037c, FLASHCOM_ID},
	/* The end of the list */
	{0x0000, 0},
};

static void mixcomwd_timerfun(unsigned long d);

static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */

static int watchdog_port;
static int mixcomwd_timer_alive;
static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
static char expect_close;

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static void mixcomwd_ping(void)
{
	outb_p(55,watchdog_port);
	return;
}

static void mixcomwd_timerfun(unsigned long d)
{
	mixcomwd_ping();

	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
}

/*
 *	Allow only one person to hold it open
 */

static int mixcomwd_open(struct inode *inode, struct file *file)
{
	if(test_and_set_bit(0,&mixcomwd_opened)) {
		return -EBUSY;
	}
	mixcomwd_ping();

	if (nowayout) {
		/*
		 * fops_get() code via open() has already done
		 * a try_module_get() so it is safe to do the
		 * __module_get().
		 */
		__module_get(THIS_MODULE);
	} else {
		if(mixcomwd_timer_alive) {
			del_timer(&mixcomwd_timer);
			mixcomwd_timer_alive=0;
		}
	}
	return nonseekable_open(inode, file);
}

static int mixcomwd_release(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		if(mixcomwd_timer_alive) {
			printk(KERN_ERR PFX "release called while internal timer alive");
			return -EBUSY;
		}
		mixcomwd_timer_alive=1;
		mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
	} else {
		printk(KERN_CRIT PFX "WDT device closed unexpectedly.  WDT will not stop!\n");
	}

	clear_bit(0,&mixcomwd_opened);
	expect_close=0;
	return 0;
}


static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
{
	if(len)
	{
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		mixcomwd_ping();
	}
	return len;
}

static int mixcomwd_ioctl(struct inode *inode, struct file *file,
	unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int status;
	static struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity = "MixCOM watchdog",
	};

	switch(cmd)
	{
		case WDIOC_GETSTATUS:
			status=mixcomwd_opened;
			if (!nowayout) {
				status|=mixcomwd_timer_alive;
			}
			if (copy_to_user(p, &status, sizeof(int))) {
				return -EFAULT;
			}
			break;
		case WDIOC_GETBOOTSTATUS:
			if (copy_to_user(p, &status, sizeof(int))) {
				return -EFAULT;
			}
			break;
		case WDIOC_GETSUPPORT:
			if (copy_to_user(argp, &ident, sizeof(ident))) {
				return -EFAULT;
			}
			break;
		case WDIOC_KEEPALIVE:
			mixcomwd_ping();
			break;
		default:
			return -ENOTTY;
	}
	return 0;
}

static const struct file_operations mixcomwd_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= mixcomwd_write,
	.ioctl		= mixcomwd_ioctl,
	.open		= mixcomwd_open,
	.release	= mixcomwd_release,
};

static struct miscdevice mixcomwd_miscdev = {
	.minor	= WATCHDOG_MINOR,
	.name	= "watchdog",
	.fops	= &mixcomwd_fops,
};

static int __init checkcard(int port, int card_id)
{
	int id;

	if (!request_region(port, 1, "MixCOM watchdog")) {
		return 0;
	}

	id=inb_p(port);
	if (card_id==MIXCOM_ID)
		id &= 0x3f;

	if (id!=card_id) {
		release_region(port, 1);
		return 0;
	}
	return 1;
}

static int __init mixcomwd_init(void)
{
	int i;
	int ret;
	int found=0;

	for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
		if (checkcard(mixcomwd_io_info[i].ioport,
			      mixcomwd_io_info[i].id)) {
			found = 1;
			watchdog_port = mixcomwd_io_info[i].ioport;
		}
	}

	if (!found) {
		printk(KERN_ERR PFX "No card detected, or port not available.\n");
		return -ENODEV;
	}

	ret = misc_register(&mixcomwd_miscdev);
	if (ret)
	{
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		goto error_misc_register_watchdog;
	}

	printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
		VERSION, watchdog_port);

	return 0;

error_misc_register_watchdog:
	release_region(watchdog_port, 1);
	watchdog_port = 0x0000;
	return ret;
}

static void __exit mixcomwd_exit(void)
{
	if (!nowayout) {
		if(mixcomwd_timer_alive) {
			printk(KERN_WARNING PFX "I quit now, hardware will"
			       " probably reboot!\n");
			del_timer_sync(&mixcomwd_timer);
			mixcomwd_timer_alive=0;
		}
	}
	misc_deregister(&mixcomwd_miscdev);
	release_region(watchdog_port,1);
}

module_init(mixcomwd_init);
module_exit(mixcomwd_exit);

MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
MODULE_DESCRIPTION("MixCom Watchdog driver");
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);