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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [machzwd.c] - Blame information for rev 1774

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1 1275 phoenix
/*
2
 *  MachZ ZF-Logic Watchdog Timer driver for Linux
3
 *
4
 *
5
 *  This program is free software; you can redistribute it and/or
6
 *  modify it under the terms of the GNU General Public License
7
 *  as published by the Free Software Foundation; either version
8
 *  2 of the License, or (at your option) any later version.
9
 *
10
 *  The author does NOT admit liability nor provide warranty for
11
 *  any of this software. This material is provided "AS-IS" in
12
 *  the hope that it may be useful for others.
13
 *
14
 *  Author: Fernando Fuganti <fuganti@conectiva.com.br>
15
 *
16
 *  Based on sbc60xxwdt.c by Jakob Oestergaard
17
 *
18
 *
19
 *  We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
20
 *  following periods:
21
 *      wd#1 - 2 seconds;
22
 *      wd#2 - 7.2 ms;
23
 *  After the expiration of wd#1, it can generate a NMI, SCI, SMI, or
24
 *  a system RESET and it starts wd#2 that unconditionaly will RESET
25
 *  the system when the counter reaches zero.
26
 *
27
 *  14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
28
 *      Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
29
 */
30
 
31
#include <linux/config.h>
32
#include <linux/module.h>
33
#include <linux/version.h>
34
#include <linux/types.h>
35
#include <linux/errno.h>
36
#include <linux/kernel.h>
37
#include <linux/timer.h>
38
#include <linux/sched.h>
39
#include <linux/miscdevice.h>
40
#include <linux/watchdog.h>
41
#include <linux/slab.h>
42
#include <linux/ioport.h>
43
#include <linux/fcntl.h>
44
#include <linux/smp_lock.h>
45
#include <asm/io.h>
46
#include <asm/uaccess.h>
47
#include <asm/system.h>
48
#include <linux/notifier.h>
49
#include <linux/reboot.h>
50
#include <linux/init.h>
51
 
52
 
53
/* ports */
54
#define ZF_IOBASE       0x218
55
#define INDEX           0x218
56
#define DATA_B          0x219
57
#define DATA_W          0x21A
58
#define DATA_D          0x21A
59
 
60
/* indexes */                   /* size */
61
#define ZFL_VERSION     0x02    /* 16   */
62
#define CONTROL         0x10    /* 16   */      
63
#define STATUS          0x12    /* 8    */
64
#define COUNTER_1       0x0C    /* 16   */
65
#define COUNTER_2       0x0E    /* 8    */
66
#define PULSE_LEN       0x0F    /* 8    */
67
 
68
/* controls */
69
#define ENABLE_WD1      0x0001
70
#define ENABLE_WD2      0x0002
71
#define RESET_WD1       0x0010
72
#define RESET_WD2       0x0020
73
#define GEN_SCI         0x0100
74
#define GEN_NMI         0x0200
75
#define GEN_SMI         0x0400
76
#define GEN_RESET       0x0800
77
 
78
 
79
/* utilities */
80
 
81
#define WD1     0
82
#define WD2     1
83
 
84
#define zf_writew(port, data)  { outb(port, INDEX); outw(data, DATA_W); }
85
#define zf_writeb(port, data)  { outb(port, INDEX); outb(data, DATA_B); }
86
#define zf_get_ZFL_version()   zf_readw(ZFL_VERSION)
87
 
88
 
89
static unsigned short zf_readw(unsigned char port)
90
{
91
        outb(port, INDEX);
92
        return inw(DATA_W);
93
}
94
 
95
static unsigned short zf_readb(unsigned char port)
96
{
97
        outb(port, INDEX);
98
        return inb(DATA_B);
99
}
100
 
101
 
102
MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
103
MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
104
MODULE_LICENSE("GPL");
105
MODULE_PARM(action, "i");
106
MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*)  1 = SMI  2 = NMI  3 = SCI");
107
 
108
#ifdef CONFIG_WATCHDOG_NOWAYOUT
109
static int nowayout = 1;
110
#else
111
static int nowayout = 0;
112
#endif
113
 
114
MODULE_PARM(nowayout,"i");
115
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
116
 
117
#define PFX "machzwd"
118
 
119
static struct watchdog_info zf_info = {
120
        options:                WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
121
        firmware_version:       1,
122
        identity:               "ZF-Logic watchdog"
123
};
124
 
125
 
126
/*
127
 * action refers to action taken when watchdog resets
128
 * 0 = GEN_RESET
129
 * 1 = GEN_SMI
130
 * 2 = GEN_NMI
131
 * 3 = GEN_SCI
132
 * defaults to GEN_RESET (0)
133
 */
134
static int action = 0;
135
static int zf_action = GEN_RESET;
136
static int zf_is_open = 0;
137
static int zf_expect_close = 0;
138
static spinlock_t zf_lock;
139
static spinlock_t zf_port_lock;
140
static struct timer_list zf_timer;
141
static unsigned long next_heartbeat = 0;
142
 
143
 
144
/* timeout for user land heart beat (10 seconds) */
145
#define ZF_USER_TIMEO (HZ*10)
146
 
147
/* timeout for hardware watchdog (~500ms) */
148
#define ZF_HW_TIMEO (HZ/2)
149
 
150
/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
151
#define ZF_CTIMEOUT 0xffff
152
 
153
#ifndef ZF_DEBUG
154
#       define dprintk(format, args...)
155
#else
156
#       define dprintk(format, args...) printk(KERN_DEBUG PFX; ":" __FUNCTION__ ":%d: " format, __LINE__ , ## args)
157
#endif
158
 
159
 
160
/* STATUS register functions */
161
 
162
static inline unsigned char zf_get_status(void)
163
{
164
        return zf_readb(STATUS);
165
}
166
 
167
static inline void zf_set_status(unsigned char new)
168
{
169
        zf_writeb(STATUS, new);
170
}
171
 
172
 
173
/* CONTROL register functions */
174
 
175
static inline unsigned short zf_get_control(void)
176
{
177
        return zf_readw(CONTROL);
178
}
179
 
180
static inline void zf_set_control(unsigned short new)
181
{
182
        zf_writew(CONTROL, new);
183
}
184
 
185
 
186
/* WD#? counter functions */
187
/*
188
 *      Just get current counter value
189
 */
190
 
191
static inline unsigned short zf_get_timer(unsigned char n)
192
{
193
        switch(n){
194
                case WD1:
195
                        return zf_readw(COUNTER_1);
196
                case WD2:
197
                        return zf_readb(COUNTER_2);
198
                default:
199
                        return 0;
200
        }
201
}
202
 
203
/*
204
 *      Just set counter value
205
 */
206
 
207
static inline void zf_set_timer(unsigned short new, unsigned char n)
208
{
209
        switch(n){
210
                case WD1:
211
                        zf_writew(COUNTER_1, new);
212
                case WD2:
213
                        zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
214
                default:
215
                        return;
216
        }
217
}
218
 
219
/*
220
 * stop hardware timer
221
 */
222
static void zf_timer_off(void)
223
{
224
        unsigned int ctrl_reg = 0;
225
        unsigned long flags;
226
 
227
        /* stop internal ping */
228
        del_timer_sync(&zf_timer);
229
 
230
        spin_lock_irqsave(&zf_port_lock, flags);
231
        /* stop watchdog timer */
232
        ctrl_reg = zf_get_control();
233
        ctrl_reg |= (ENABLE_WD1|ENABLE_WD2);    /* disable wd1 and wd2 */
234
        ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
235
        zf_set_control(ctrl_reg);
236
        spin_unlock_irqrestore(&zf_port_lock, flags);
237
 
238
        printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");
239
}
240
 
241
 
242
/*
243
 * start hardware timer
244
 */
245
static void zf_timer_on(void)
246
{
247
        unsigned int ctrl_reg = 0;
248
        unsigned long flags;
249
 
250
        spin_lock_irqsave(&zf_port_lock, flags);
251
 
252
        zf_writeb(PULSE_LEN, 0xff);
253
 
254
        zf_set_timer(ZF_CTIMEOUT, WD1);
255
 
256
        /* user land ping */
257
        next_heartbeat = jiffies + ZF_USER_TIMEO;
258
 
259
        /* start the timer for internal ping */
260
        zf_timer.expires = jiffies + ZF_HW_TIMEO;
261
 
262
        add_timer(&zf_timer);
263
 
264
        /* start watchdog timer */
265
        ctrl_reg = zf_get_control();
266
        ctrl_reg |= (ENABLE_WD1|zf_action);
267
        zf_set_control(ctrl_reg);
268
        spin_unlock_irqrestore(&zf_port_lock, flags);
269
 
270
        printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
271
}
272
 
273
 
274
static void zf_ping(unsigned long data)
275
{
276
        unsigned int ctrl_reg = 0;
277
        unsigned long flags;
278
 
279
        zf_writeb(COUNTER_2, 0xff);
280
 
281
        if(time_before(jiffies, next_heartbeat)){
282
 
283
                dprintk("time_before: %ld\n", next_heartbeat - jiffies);
284
 
285
                /*
286
                 * reset event is activated by transition from 0 to 1 on
287
                 * RESET_WD1 bit and we assume that it is already zero...
288
                 */
289
 
290
                spin_lock_irqsave(&zf_port_lock, flags);
291
                ctrl_reg = zf_get_control();
292
                ctrl_reg |= RESET_WD1;
293
                zf_set_control(ctrl_reg);
294
 
295
                /* ...and nothing changes until here */
296
                ctrl_reg &= ~(RESET_WD1);
297
                zf_set_control(ctrl_reg);
298
                spin_unlock_irqrestore(&zf_port_lock, flags);
299
 
300
                zf_timer.expires = jiffies + ZF_HW_TIMEO;
301
                add_timer(&zf_timer);
302
        }else{
303
                printk(KERN_CRIT PFX ": I will reset your machine\n");
304
        }
305
}
306
 
307
static ssize_t zf_write(struct file *file, const char *buf, size_t count,
308
                                                                loff_t *ppos)
309
{
310
        /*  Can't seek (pwrite) on this device  */
311
        if (ppos != &file->f_pos)
312
                return -ESPIPE;
313
 
314
        /* See if we got the magic character */
315
        if(count){
316
 
317
                /*
318
                 * no need to check for close confirmation
319
                 * no way to disable watchdog ;)
320
                 */
321
                if (!nowayout) {
322
                        size_t ofs;
323
 
324
                        /*
325
                         * note: just in case someone wrote the
326
                         * magic character five months ago...
327
                         */
328
                        zf_expect_close = 0;
329
 
330
                        /* now scan */
331
                        for(ofs = 0; ofs != count; ofs++){
332
                                char c;
333
                                if(get_user(c, buf+ofs))
334
                                        return -EFAULT;
335
                                if(c == 'V'){
336
                                        zf_expect_close = 1;
337
                                        dprintk("zf_expect_close 1\n");
338
                                }
339
                        }
340
                }
341
                /*
342
                 * Well, anyhow someone wrote to us,
343
                 * we should return that favour
344
                 */
345
                next_heartbeat = jiffies + ZF_USER_TIMEO;
346
                dprintk("user ping at %ld\n", jiffies);
347
 
348
                return 1;
349
        }
350
 
351
        return 0;
352
}
353
 
354
static ssize_t zf_read(struct file *file, char *buf, size_t count,
355
                                                        loff_t *ppos)
356
{
357
        return -EINVAL;
358
}
359
 
360
 
361
 
362
static int zf_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
363
        unsigned long arg)
364
{
365
        switch(cmd){
366
                case WDIOC_GETSUPPORT:
367
                        if (copy_to_user((struct watchdog_info *)arg,
368
                                         &zf_info, sizeof(zf_info)))
369
                                return -EFAULT;
370
                        break;
371
 
372
                case WDIOC_GETSTATUS:
373
                        if (copy_to_user((int *)arg, &zf_is_open, sizeof(int)))
374
                                return -EFAULT;
375
                        break;
376
 
377
                case WDIOC_KEEPALIVE:
378
                        zf_ping(0);
379
                        break;
380
 
381
                default:
382
                        return -ENOTTY;
383
        }
384
 
385
        return 0;
386
}
387
 
388
static int zf_open(struct inode *inode, struct file *file)
389
{
390
        switch(MINOR(inode->i_rdev)){
391
                case WATCHDOG_MINOR:
392
                        spin_lock(&zf_lock);
393
                        if(zf_is_open){
394
                                spin_unlock(&zf_lock);
395
                                return -EBUSY;
396
                        }
397
 
398
                        if (nowayout) {
399
                                MOD_INC_USE_COUNT;
400
                        }
401
                        zf_is_open = 1;
402
 
403
                        spin_unlock(&zf_lock);
404
 
405
                        zf_timer_on();
406
 
407
                        return 0;
408
                default:
409
                        return -ENODEV;
410
        }
411
}
412
 
413
static int zf_close(struct inode *inode, struct file *file)
414
{
415
        if(MINOR(inode->i_rdev) == WATCHDOG_MINOR){
416
 
417
                if(zf_expect_close){
418
                        zf_timer_off();
419
                } else {
420
                        del_timer(&zf_timer);
421
                        printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");
422
                }
423
 
424
                spin_lock(&zf_lock);
425
                zf_is_open = 0;
426
                spin_unlock(&zf_lock);
427
 
428
                zf_expect_close = 0;
429
        }
430
 
431
        return 0;
432
}
433
 
434
/*
435
 * Notifier for system down
436
 */
437
 
438
static int zf_notify_sys(struct notifier_block *this, unsigned long code,
439
                                                                void *unused)
440
{
441
        if(code == SYS_DOWN || code == SYS_HALT){
442
                zf_timer_off();
443
        }
444
 
445
        return NOTIFY_DONE;
446
}
447
 
448
 
449
 
450
 
451
static struct file_operations zf_fops = {
452
        owner:          THIS_MODULE,
453
        read:           zf_read,
454
        write:          zf_write,
455
        ioctl:          zf_ioctl,
456
        open:           zf_open,
457
        release:        zf_close,
458
};
459
 
460
static struct miscdevice zf_miscdev = {
461
        WATCHDOG_MINOR,
462
        "watchdog",
463
        &zf_fops
464
};
465
 
466
 
467
/*
468
 * The device needs to learn about soft shutdowns in order to
469
 * turn the timebomb registers off.
470
 */
471
static struct notifier_block zf_notifier = {
472
        zf_notify_sys,
473
        NULL,
474
 
475
};
476
 
477
static void __init zf_show_action(int act)
478
{
479
        char *str[] = { "RESET", "SMI", "NMI", "SCI" };
480
 
481
        printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
482
}
483
 
484
static int __init zf_init(void)
485
{
486
        int ret;
487
 
488
        printk(KERN_INFO PFX ": MachZ ZF-Logic Watchdog driver initializing.\n");
489
 
490
        ret = zf_get_ZFL_version();
491
        printk("%#x\n", ret);
492
        if((!ret) || (ret != 0xffff)){
493
                printk(KERN_WARNING PFX ": no ZF-Logic found\n");
494
                return -ENODEV;
495
        }
496
 
497
        if((action <= 3) && (action >= 0)){
498
                zf_action = zf_action>>action;
499
        } else
500
                action = 0;
501
 
502
        zf_show_action(action);
503
 
504
        spin_lock_init(&zf_lock);
505
        spin_lock_init(&zf_port_lock);
506
 
507
        ret = misc_register(&zf_miscdev);
508
        if (ret){
509
                printk(KERN_ERR "can't misc_register on minor=%d\n",
510
                                                        WATCHDOG_MINOR);
511
                goto out;
512
        }
513
 
514
        if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){
515
                printk(KERN_ERR "cannot reserve I/O ports at %d\n",
516
                                                        ZF_IOBASE);
517
                ret = -EBUSY;
518
                goto no_region;
519
        }
520
 
521
        ret = register_reboot_notifier(&zf_notifier);
522
        if(ret){
523
                printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
524
                                                                        ret);
525
                goto no_reboot;
526
        }
527
 
528
        zf_set_status(0);
529
        zf_set_control(0);
530
 
531
        /* this is the timer that will do the hard work */
532
        init_timer(&zf_timer);
533
        zf_timer.function = zf_ping;
534
        zf_timer.data = 0;
535
 
536
        return 0;
537
 
538
no_reboot:
539
        release_region(ZF_IOBASE, 3);
540
no_region:
541
        misc_deregister(&zf_miscdev);
542
out:
543
        return ret;
544
}
545
 
546
 
547
void __exit zf_exit(void)
548
{
549
        zf_timer_off();
550
 
551
        misc_deregister(&zf_miscdev);
552
        unregister_reboot_notifier(&zf_notifier);
553
        release_region(ZF_IOBASE, 3);
554
}
555
 
556
module_init(zf_init);
557
module_exit(zf_exit);

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