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31#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/types.h>
34#include <linux/timer.h>
35#include <linux/jiffies.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/io.h>
44#include <linux/uaccess.h>
45
46#include <asm/system.h>
47
48
49#define ZF_IOBASE 0x218
50#define INDEX 0x218
51#define DATA_B 0x219
52#define DATA_W 0x21A
53#define DATA_D 0x21A
54
55
56#define ZFL_VERSION 0x02
57#define CONTROL 0x10
58#define STATUS 0x12
59#define COUNTER_1 0x0C
60#define COUNTER_2 0x0E
61#define PULSE_LEN 0x0F
62
63
64#define ENABLE_WD1 0x0001
65#define ENABLE_WD2 0x0002
66#define RESET_WD1 0x0010
67#define RESET_WD2 0x0020
68#define GEN_SCI 0x0100
69#define GEN_NMI 0x0200
70#define GEN_SMI 0x0400
71#define GEN_RESET 0x0800
72
73
74
75
76#define WD1 0
77#define WD2 1
78
79#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
80#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
81#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
82
83
84static unsigned short zf_readw(unsigned char port)
85{
86 outb(port, INDEX);
87 return inw(DATA_W);
88}
89
90
91MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
92MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
93MODULE_LICENSE("GPL");
94MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
95
96static int nowayout = WATCHDOG_NOWAYOUT;
97module_param(nowayout, int, 0);
98MODULE_PARM_DESC(nowayout,
99 "Watchdog cannot be stopped once started (default="
100 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
101
102#define PFX "machzwd"
103
104static const struct watchdog_info zf_info = {
105 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
106 .firmware_version = 1,
107 .identity = "ZF-Logic watchdog",
108};
109
110
111
112
113
114
115
116
117
118
119static int action;
120module_param(action, int, 0);
121MODULE_PARM_DESC(action, "after watchdog resets, generate: "
122 "0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
123
124static void zf_ping(unsigned long data);
125
126static int zf_action = GEN_RESET;
127static unsigned long zf_is_open;
128static char zf_expect_close;
129static DEFINE_SPINLOCK(zf_port_lock);
130static DEFINE_TIMER(zf_timer, zf_ping, 0, 0);
131static unsigned long next_heartbeat;
132
133
134
135#define ZF_USER_TIMEO (HZ*10)
136
137
138#define ZF_HW_TIMEO (HZ/2)
139
140
141#define ZF_CTIMEOUT 0xffff
142
143#ifndef ZF_DEBUG
144# define dprintk(format, args...)
145#else
146# define dprintk(format, args...) printk(KERN_DEBUG PFX \
147 ":%s:%d: " format, __func__, __LINE__ , ## args)
148#endif
149
150
151static inline void zf_set_status(unsigned char new)
152{
153 zf_writeb(STATUS, new);
154}
155
156
157
158
159static inline unsigned short zf_get_control(void)
160{
161 return zf_readw(CONTROL);
162}
163
164static inline void zf_set_control(unsigned short new)
165{
166 zf_writew(CONTROL, new);
167}
168
169
170
171
172
173
174
175static inline void zf_set_timer(unsigned short new, unsigned char n)
176{
177 switch (n) {
178 case WD1:
179 zf_writew(COUNTER_1, new);
180 case WD2:
181 zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
182 default:
183 return;
184 }
185}
186
187
188
189
190static void zf_timer_off(void)
191{
192 unsigned int ctrl_reg = 0;
193 unsigned long flags;
194
195
196 del_timer_sync(&zf_timer);
197
198 spin_lock_irqsave(&zf_port_lock, flags);
199
200 ctrl_reg = zf_get_control();
201 ctrl_reg |= (ENABLE_WD1|ENABLE_WD2);
202 ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
203 zf_set_control(ctrl_reg);
204 spin_unlock_irqrestore(&zf_port_lock, flags);
205
206 printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");
207}
208
209
210
211
212
213static void zf_timer_on(void)
214{
215 unsigned int ctrl_reg = 0;
216 unsigned long flags;
217
218 spin_lock_irqsave(&zf_port_lock, flags);
219
220 zf_writeb(PULSE_LEN, 0xff);
221
222 zf_set_timer(ZF_CTIMEOUT, WD1);
223
224
225 next_heartbeat = jiffies + ZF_USER_TIMEO;
226
227
228 mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
229
230
231 ctrl_reg = zf_get_control();
232 ctrl_reg |= (ENABLE_WD1|zf_action);
233 zf_set_control(ctrl_reg);
234 spin_unlock_irqrestore(&zf_port_lock, flags);
235
236 printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
237}
238
239
240static void zf_ping(unsigned long data)
241{
242 unsigned int ctrl_reg = 0;
243 unsigned long flags;
244
245 zf_writeb(COUNTER_2, 0xff);
246
247 if (time_before(jiffies, next_heartbeat)) {
248 dprintk("time_before: %ld\n", next_heartbeat - jiffies);
249
250
251
252
253
254 spin_lock_irqsave(&zf_port_lock, flags);
255 ctrl_reg = zf_get_control();
256 ctrl_reg |= RESET_WD1;
257 zf_set_control(ctrl_reg);
258
259
260 ctrl_reg &= ~(RESET_WD1);
261 zf_set_control(ctrl_reg);
262 spin_unlock_irqrestore(&zf_port_lock, flags);
263
264 mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
265 } else
266 printk(KERN_CRIT PFX ": I will reset your machine\n");
267}
268
269static ssize_t zf_write(struct file *file, const char __user *buf, size_t count,
270 loff_t *ppos)
271{
272
273 if (count) {
274
275
276
277
278 if (!nowayout) {
279 size_t ofs;
280
281
282
283
284 zf_expect_close = 0;
285
286
287 for (ofs = 0; ofs != count; ofs++) {
288 char c;
289 if (get_user(c, buf + ofs))
290 return -EFAULT;
291 if (c == 'V') {
292 zf_expect_close = 42;
293 dprintk("zf_expect_close = 42\n");
294 }
295 }
296 }
297
298
299
300
301
302 next_heartbeat = jiffies + ZF_USER_TIMEO;
303 dprintk("user ping at %ld\n", jiffies);
304 }
305 return count;
306}
307
308static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
309{
310 void __user *argp = (void __user *)arg;
311 int __user *p = argp;
312 switch (cmd) {
313 case WDIOC_GETSUPPORT:
314 if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
315 return -EFAULT;
316 break;
317 case WDIOC_GETSTATUS:
318 case WDIOC_GETBOOTSTATUS:
319 return put_user(0, p);
320 case WDIOC_KEEPALIVE:
321 zf_ping(0);
322 break;
323 default:
324 return -ENOTTY;
325 }
326 return 0;
327}
328
329static int zf_open(struct inode *inode, struct file *file)
330{
331 if (test_and_set_bit(0, &zf_is_open))
332 return -EBUSY;
333 if (nowayout)
334 __module_get(THIS_MODULE);
335 zf_timer_on();
336 return nonseekable_open(inode, file);
337}
338
339static int zf_close(struct inode *inode, struct file *file)
340{
341 if (zf_expect_close == 42)
342 zf_timer_off();
343 else {
344 del_timer(&zf_timer);
345 printk(KERN_ERR PFX ": device file closed unexpectedly. "
346 "Will not stop the WDT!\n");
347 }
348 clear_bit(0, &zf_is_open);
349 zf_expect_close = 0;
350 return 0;
351}
352
353
354
355
356
357static int zf_notify_sys(struct notifier_block *this, unsigned long code,
358 void *unused)
359{
360 if (code == SYS_DOWN || code == SYS_HALT)
361 zf_timer_off();
362 return NOTIFY_DONE;
363}
364
365static const struct file_operations zf_fops = {
366 .owner = THIS_MODULE,
367 .llseek = no_llseek,
368 .write = zf_write,
369 .unlocked_ioctl = zf_ioctl,
370 .open = zf_open,
371 .release = zf_close,
372};
373
374static struct miscdevice zf_miscdev = {
375 .minor = WATCHDOG_MINOR,
376 .name = "watchdog",
377 .fops = &zf_fops,
378};
379
380
381
382
383
384
385static struct notifier_block zf_notifier = {
386 .notifier_call = zf_notify_sys,
387};
388
389static void __init zf_show_action(int act)
390{
391 static const char * const str[] = { "RESET", "SMI", "NMI", "SCI" };
392
393 printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
394}
395
396static int __init zf_init(void)
397{
398 int ret;
399
400 printk(KERN_INFO PFX
401 ": MachZ ZF-Logic Watchdog driver initializing.\n");
402
403 ret = zf_get_ZFL_version();
404 if (!ret || ret == 0xffff) {
405 printk(KERN_WARNING PFX ": no ZF-Logic found\n");
406 return -ENODEV;
407 }
408
409 if (action <= 3 && action >= 0)
410 zf_action = zf_action >> action;
411 else
412 action = 0;
413
414 zf_show_action(action);
415
416 if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) {
417 printk(KERN_ERR "cannot reserve I/O ports at %d\n",
418 ZF_IOBASE);
419 ret = -EBUSY;
420 goto no_region;
421 }
422
423 ret = register_reboot_notifier(&zf_notifier);
424 if (ret) {
425 printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
426 ret);
427 goto no_reboot;
428 }
429
430 ret = misc_register(&zf_miscdev);
431 if (ret) {
432 printk(KERN_ERR "can't misc_register on minor=%d\n",
433 WATCHDOG_MINOR);
434 goto no_misc;
435 }
436
437 zf_set_status(0);
438 zf_set_control(0);
439
440 return 0;
441
442no_misc:
443 unregister_reboot_notifier(&zf_notifier);
444no_reboot:
445 release_region(ZF_IOBASE, 3);
446no_region:
447 return ret;
448}
449
450
451static void __exit zf_exit(void)
452{
453 zf_timer_off();
454
455 misc_deregister(&zf_miscdev);
456 unregister_reboot_notifier(&zf_notifier);
457 release_region(ZF_IOBASE, 3);
458}
459
460module_init(zf_init);
461module_exit(zf_exit);
462