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remove mentionings of devfs in documentation
[linux-2.6/linux-mips.git] / drivers / sbus / char / cpwatchdog.c
blob40b6fc86f6a8301a5c0fec1e2c3a6dba5a807d4f
1 /* cpwatchdog.c - driver implementation for hardware watchdog
2 * timers found on Sun Microsystems CP1400 and CP1500 boards.
3 *
4 * This device supports both the generic Linux watchdog
5 * interface and Solaris-compatible ioctls as best it is
6 * able.
7 *
8 * NOTE: CP1400 systems appear to have a defective intr_mask
9 * register on the PLD, preventing the disabling of
10 * timer interrupts. We use a timer to periodically
11 * reset 'stopped' watchdogs on affected platforms.
12 *
13 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/errno.h>
20 #include <linux/major.h>
21 #include <linux/init.h>
22 #include <linux/miscdevice.h>
23 #include <linux/sched.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioport.h>
26 #include <linux/timer.h>
27 #include <linux/smp_lock.h>
28 #include <asm/irq.h>
29 #include <asm/ebus.h>
30 #include <asm/oplib.h>
31 #include <asm/uaccess.h>
32
33 #include <asm/watchdog.h>
34
35 #define WD_OBPNAME "watchdog"
36 #define WD_BADMODEL "SUNW,501-5336"
37 #define WD_BTIMEOUT (jiffies + (HZ * 1000))
38 #define WD_BLIMIT 0xFFFF
39
40 #define WD0_DEVNAME "watchdog0"
41 #define WD1_DEVNAME "watchdog1"
42 #define WD2_DEVNAME "watchdog2"
43
44 #define WD0_MINOR 212
45 #define WD1_MINOR 213
46 #define WD2_MINOR 214
47
48
49 /* Internal driver definitions
50 */
51 #define WD0_ID 0 /* Watchdog0 */
52 #define WD1_ID 1 /* Watchdog1 */
53 #define WD2_ID 2 /* Watchdog2 */
54 #define WD_NUMDEVS 3 /* Device contains 3 timers */
55
56 #define WD_INTR_OFF 0 /* Interrupt disable value */
57 #define WD_INTR_ON 1 /* Interrupt enable value */
58
59 #define WD_STAT_INIT 0x01 /* Watchdog timer is initialized */
60 #define WD_STAT_BSTOP 0x02 /* Watchdog timer is brokenstopped */
61 #define WD_STAT_SVCD 0x04 /* Watchdog interrupt occurred */
62
63 /* Register value definitions
64 */
65 #define WD0_INTR_MASK 0x01 /* Watchdog device interrupt masks */
66 #define WD1_INTR_MASK 0x02
67 #define WD2_INTR_MASK 0x04
68
69 #define WD_S_RUNNING 0x01 /* Watchdog device status running */
70 #define WD_S_EXPIRED 0x02 /* Watchdog device status expired */
71
72 /* Sun uses Altera PLD EPF8820ATC144-4
73 * providing three hardware watchdogs:
74 *
75 * 1) RIC - sends an interrupt when triggered
76 * 2) XIR - asserts XIR_B_RESET when triggered, resets CPU
77 * 3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board
78 *
79 *** Timer register block definition (struct wd_timer_regblk)
80 *
81 * dcntr and limit registers (halfword access):
82 * -------------------
83 * | 15 | ...| 1 | 0 |
84 * -------------------
85 * |- counter val -|
86 * -------------------
87 * dcntr - Current 16-bit downcounter value.
88 * When downcounter reaches '0' watchdog expires.
89 * Reading this register resets downcounter with 'limit' value.
90 * limit - 16-bit countdown value in 1/10th second increments.
91 * Writing this register begins countdown with input value.
92 * Reading from this register does not affect counter.
93 * NOTES: After watchdog reset, dcntr and limit contain '1'
94 *
95 * status register (byte access):
96 * ---------------------------
97 * | 7 | ... | 2 | 1 | 0 |
98 * --------------+------------
99 * |- UNUSED -| EXP | RUN |
100 * ---------------------------
101 * status- Bit 0 - Watchdog is running
102 * Bit 1 - Watchdog has expired
103 *
104 *** PLD register block definition (struct wd_pld_regblk)
105 *
106 * intr_mask register (byte access):
107 * ---------------------------------
108 * | 7 | ... | 3 | 2 | 1 | 0 |
109 * +-------------+------------------
110 * |- UNUSED -| WD3 | WD2 | WD1 |
111 * ---------------------------------
112 * WD3 - 1 == Interrupt disabled for watchdog 3
113 * WD2 - 1 == Interrupt disabled for watchdog 2
114 * WD1 - 1 == Interrupt disabled for watchdog 1
115 *
116 * pld_status register (byte access):
117 * UNKNOWN, MAGICAL MYSTERY REGISTER
118 *
119 */
120 #define WD_TIMER_REGSZ 16
121 #define WD0_OFF 0
122 #define WD1_OFF (WD_TIMER_REGSZ * 1)
123 #define WD2_OFF (WD_TIMER_REGSZ * 2)
124 #define PLD_OFF (WD_TIMER_REGSZ * 3)
125
126 #define WD_DCNTR 0x00
127 #define WD_LIMIT 0x04
128 #define WD_STATUS 0x08
129
130 #define PLD_IMASK (PLD_OFF + 0x00)
131 #define PLD_STATUS (PLD_OFF + 0x04)
132
133 /* Individual timer structure
134 */
135 struct wd_timer {
136 __u16 timeout;
137 __u8 intr_mask;
138 unsigned char runstatus;
139 void __iomem *regs;
140 };
141
142 /* Device structure
143 */
144 struct wd_device {
145 int irq;
146 spinlock_t lock;
147 unsigned char isbaddoggie; /* defective PLD */
148 unsigned char opt_enable;
149 unsigned char opt_reboot;
150 unsigned short opt_timeout;
151 unsigned char initialized;
152 struct wd_timer watchdog[WD_NUMDEVS];
153 void __iomem *regs;
154 };
155
156 static struct wd_device wd_dev = {
157 0, SPIN_LOCK_UNLOCKED, 0, 0, 0, 0,
158 };
159
160 static struct timer_list wd_timer;
161
162 static int wd0_timeout = 0;
163 static int wd1_timeout = 0;
164 static int wd2_timeout = 0;
165
166 #ifdef MODULE
167 module_param (wd0_timeout, int, 0);
168 MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
169 module_param (wd1_timeout, int, 0);
170 MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
171 module_param (wd2_timeout, int, 0);
172 MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs");
173
174 MODULE_AUTHOR
175 ("Eric Brower <ebrower@usa.net>");
176 MODULE_DESCRIPTION
177 ("Hardware watchdog driver for Sun Microsystems CP1400/1500");
178 MODULE_LICENSE("GPL");
179 MODULE_SUPPORTED_DEVICE
180 ("watchdog");
181 #endif /* ifdef MODULE */
182
183 /* Forward declarations of internal methods
184 */
185 #ifdef WD_DEBUG
186 static void wd_dumpregs(void);
187 #endif
188 static irqreturn_t wd_interrupt(int irq, void *dev_id, struct pt_regs *regs);
189 static void wd_toggleintr(struct wd_timer* pTimer, int enable);
190 static void wd_pingtimer(struct wd_timer* pTimer);
191 static void wd_starttimer(struct wd_timer* pTimer);
192 static void wd_resetbrokentimer(struct wd_timer* pTimer);
193 static void wd_stoptimer(struct wd_timer* pTimer);
194 static void wd_brokentimer(unsigned long data);
195 static int wd_getstatus(struct wd_timer* pTimer);
196
197 /* PLD expects words to be written in LSB format,
198 * so we must flip all words prior to writing them to regs
199 */
200 static inline unsigned short flip_word(unsigned short word)
201 {
202 return ((word & 0xff) << 8) | ((word >> 8) & 0xff);
203 }
204
205 #define wd_writew(val, addr) (writew(flip_word(val), addr))
206 #define wd_readw(addr) (flip_word(readw(addr)))
207 #define wd_writeb(val, addr) (writeb(val, addr))
208 #define wd_readb(addr) (readb(addr))
209
210
211 /* CP1400s seem to have broken PLD implementations--
212 * the interrupt_mask register cannot be written, so
213 * no timer interrupts can be masked within the PLD.
214 */
215 static inline int wd_isbroken(void)
216 {
217 /* we could test this by read/write/read/restore
218 * on the interrupt mask register only if OBP
219 * 'watchdog-enable?' == FALSE, but it seems
220 * ubiquitous on CP1400s
221 */
222 char val[32];
223 prom_getproperty(prom_root_node, "model", val, sizeof(val));
224 return((!strcmp(val, WD_BADMODEL)) ? 1 : 0);
225 }
226
227 /* Retrieve watchdog-enable? option from OBP
228 * Returns 0 if false, 1 if true
229 */
230 static inline int wd_opt_enable(void)
231 {
232 int opt_node;
233
234 opt_node = prom_getchild(prom_root_node);
235 opt_node = prom_searchsiblings(opt_node, "options");
236 return((-1 == prom_getint(opt_node, "watchdog-enable?")) ? 0 : 1);
237 }
238
239 /* Retrieve watchdog-reboot? option from OBP
240 * Returns 0 if false, 1 if true
241 */
242 static inline int wd_opt_reboot(void)
243 {
244 int opt_node;
245
246 opt_node = prom_getchild(prom_root_node);
247 opt_node = prom_searchsiblings(opt_node, "options");
248 return((-1 == prom_getint(opt_node, "watchdog-reboot?")) ? 0 : 1);
249 }
250
251 /* Retrieve watchdog-timeout option from OBP
252 * Returns OBP value, or 0 if not located
253 */
254 static inline int wd_opt_timeout(void)
255 {
256 int opt_node;
257 char value[32];
258 char *p = value;
259
260 opt_node = prom_getchild(prom_root_node);
261 opt_node = prom_searchsiblings(opt_node, "options");
262 opt_node = prom_getproperty(opt_node,
263 "watchdog-timeout",
264 value,
265 sizeof(value));
266 if(-1 != opt_node) {
267 /* atoi implementation */
268 for(opt_node = 0; /* nop */; p++) {
269 if(*p >= '0' && *p <= '9') {
270 opt_node = (10*opt_node)+(*p-'0');
271 }
272 else {
273 break;
274 }
275 }
276 }
277 return((-1 == opt_node) ? (0) : (opt_node));
278 }
279
280 static int wd_open(struct inode *inode, struct file *f)
281 {
282 switch(iminor(inode))
283 {
284 case WD0_MINOR:
285 f->private_data = &wd_dev.watchdog[WD0_ID];
286 break;
287 case WD1_MINOR:
288 f->private_data = &wd_dev.watchdog[WD1_ID];
289 break;
290 case WD2_MINOR:
291 f->private_data = &wd_dev.watchdog[WD2_ID];
292 break;
293 default:
294 return(-ENODEV);
295 }
296
297 /* Register IRQ on first open of device */
298 if(0 == wd_dev.initialized)
299 {
300 if (request_irq(wd_dev.irq,
301 &wd_interrupt,
302 IRQF_SHARED,
303 WD_OBPNAME,
304 (void *)wd_dev.regs)) {
305 printk("%s: Cannot register IRQ %d\n",
306 WD_OBPNAME, wd_dev.irq);
307 return(-EBUSY);
308 }
309 wd_dev.initialized = 1;
310 }
311
312 return(nonseekable_open(inode, f));
313 }
314
315 static int wd_release(struct inode *inode, struct file *file)
316 {
317 return 0;
318 }
319
320 static int wd_ioctl(struct inode *inode, struct file *file,
321 unsigned int cmd, unsigned long arg)
322 {
323 int setopt = 0;
324 struct wd_timer* pTimer = (struct wd_timer*)file->private_data;
325 void __user *argp = (void __user *)arg;
326 struct watchdog_info info = {
327 0,
328 0,
329 "Altera EPF8820ATC144-4"
330 };
331
332 if(NULL == pTimer) {
333 return(-EINVAL);
334 }
335
336 switch(cmd)
337 {
338 /* Generic Linux IOCTLs */
339 case WDIOC_GETSUPPORT:
340 if(copy_to_user(argp, &info, sizeof(struct watchdog_info))) {
341 return(-EFAULT);
342 }
343 break;
344 case WDIOC_GETSTATUS:
345 case WDIOC_GETBOOTSTATUS:
346 if (put_user(0, (int __user *)argp))
347 return -EFAULT;
348 break;
349 case WDIOC_KEEPALIVE:
350 wd_pingtimer(pTimer);
351 break;
352 case WDIOC_SETOPTIONS:
353 if(copy_from_user(&setopt, argp, sizeof(unsigned int))) {
354 return -EFAULT;
355 }
356 if(setopt & WDIOS_DISABLECARD) {
357 if(wd_dev.opt_enable) {
358 printk(
359 "%s: cannot disable watchdog in ENABLED mode\n",
360 WD_OBPNAME);
361 return(-EINVAL);
362 }
363 wd_stoptimer(pTimer);
364 }
365 else if(setopt & WDIOS_ENABLECARD) {
366 wd_starttimer(pTimer);
367 }
368 else {
369 return(-EINVAL);
370 }
371 break;
372 /* Solaris-compatible IOCTLs */
373 case WIOCGSTAT:
374 setopt = wd_getstatus(pTimer);
375 if(copy_to_user(argp, &setopt, sizeof(unsigned int))) {
376 return(-EFAULT);
377 }
378 break;
379 case WIOCSTART:
380 wd_starttimer(pTimer);
381 break;
382 case WIOCSTOP:
383 if(wd_dev.opt_enable) {
384 printk("%s: cannot disable watchdog in ENABLED mode\n",
385 WD_OBPNAME);
386 return(-EINVAL);
387 }
388 wd_stoptimer(pTimer);
389 break;
390 default:
391 return(-EINVAL);
392 }
393 return(0);
394 }
395
396 static long wd_compat_ioctl(struct file *file, unsigned int cmd,
397 unsigned long arg)
398 {
399 int rval = -ENOIOCTLCMD;
400
401 switch (cmd) {
402 /* solaris ioctls are specific to this driver */
403 case WIOCSTART:
404 case WIOCSTOP:
405 case WIOCGSTAT:
406 lock_kernel();
407 rval = wd_ioctl(file->f_dentry->d_inode, file, cmd, arg);
408 unlock_kernel();
409 break;
410 /* everything else is handled by the generic compat layer */
411 default:
412 break;
413 }
414
415 return rval;
416 }
417
418 static ssize_t wd_write(struct file *file,
419 const char __user *buf,
420 size_t count,
421 loff_t *ppos)
422 {
423 struct wd_timer* pTimer = (struct wd_timer*)file->private_data;
424
425 if(NULL == pTimer) {
426 return(-EINVAL);
427 }
428
429 if (count) {
430 wd_pingtimer(pTimer);
431 return 1;
432 }
433 return 0;
434 }
435
436 static ssize_t wd_read(struct file * file, char __user *buffer,
437 size_t count, loff_t *ppos)
438 {
439 #ifdef WD_DEBUG
440 wd_dumpregs();
441 return(0);
442 #else
443 return(-EINVAL);
444 #endif /* ifdef WD_DEBUG */
445 }
446
447 static irqreturn_t wd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
448 {
449 /* Only WD0 will interrupt-- others are NMI and we won't
450 * see them here....
451 */
452 spin_lock_irq(&wd_dev.lock);
453 if((unsigned long)wd_dev.regs == (unsigned long)dev_id)
454 {
455 wd_stoptimer(&wd_dev.watchdog[WD0_ID]);
456 wd_dev.watchdog[WD0_ID].runstatus |= WD_STAT_SVCD;
457 }
458 spin_unlock_irq(&wd_dev.lock);
459 return IRQ_HANDLED;
460 }
461
462 static struct file_operations wd_fops = {
463 .owner = THIS_MODULE,
464 .ioctl = wd_ioctl,
465 .compat_ioctl = wd_compat_ioctl,
466 .open = wd_open,
467 .write = wd_write,
468 .read = wd_read,
469 .release = wd_release,
470 };
471
472 static struct miscdevice wd0_miscdev = { WD0_MINOR, WD0_DEVNAME, &wd_fops };
473 static struct miscdevice wd1_miscdev = { WD1_MINOR, WD1_DEVNAME, &wd_fops };
474 static struct miscdevice wd2_miscdev = { WD2_MINOR, WD2_DEVNAME, &wd_fops };
475
476 #ifdef WD_DEBUG
477 static void wd_dumpregs(void)
478 {
479 /* Reading from downcounters initiates watchdog countdown--
480 * Example is included below for illustration purposes.
481 */
482 int i;
483 printk("%s: dumping register values\n", WD_OBPNAME);
484 for(i = WD0_ID; i < WD_NUMDEVS; ++i) {
485 /* printk("\t%s%i: dcntr at 0x%lx: 0x%x\n",
486 * WD_OBPNAME,
487 * i,
488 * (unsigned long)(&wd_dev.watchdog[i].regs->dcntr),
489 * readw(&wd_dev.watchdog[i].regs->dcntr));
490 */
491 printk("\t%s%i: limit at 0x%lx: 0x%x\n",
492 WD_OBPNAME,
493 i,
494 (unsigned long)(&wd_dev.watchdog[i].regs->limit),
495 readw(&wd_dev.watchdog[i].regs->limit));
496 printk("\t%s%i: status at 0x%lx: 0x%x\n",
497 WD_OBPNAME,
498 i,
499 (unsigned long)(&wd_dev.watchdog[i].regs->status),
500 readb(&wd_dev.watchdog[i].regs->status));
501 printk("\t%s%i: driver status: 0x%x\n",
502 WD_OBPNAME,
503 i,
504 wd_getstatus(&wd_dev.watchdog[i]));
505 }
506 printk("\tintr_mask at %p: 0x%x\n",
507 wd_dev.regs + PLD_IMASK,
508 readb(wd_dev.regs + PLD_IMASK));
509 printk("\tpld_status at %p: 0x%x\n",
510 wd_dev.regs + PLD_STATUS,
511 readb(wd_dev.regs + PLD_STATUS));
512 }
513 #endif
514
515 /* Enable or disable watchdog interrupts
516 * Because of the CP1400 defect this should only be
517 * called during initialzation or by wd_[start|stop]timer()
518 *
519 * pTimer - pointer to timer device, or NULL to indicate all timers
520 * enable - non-zero to enable interrupts, zero to disable
521 */
522 static void wd_toggleintr(struct wd_timer* pTimer, int enable)
523 {
524 unsigned char curregs = wd_readb(wd_dev.regs + PLD_IMASK);
525 unsigned char setregs =
526 (NULL == pTimer) ?
527 (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) :
528 (pTimer->intr_mask);
529
530 (WD_INTR_ON == enable) ?
531 (curregs &= ~setregs):
532 (curregs |= setregs);
533
534 wd_writeb(curregs, wd_dev.regs + PLD_IMASK);
535 return;
536 }
537
538 /* Reset countdown timer with 'limit' value and continue countdown.
539 * This will not start a stopped timer.
540 *
541 * pTimer - pointer to timer device
542 */
543 static void wd_pingtimer(struct wd_timer* pTimer)
544 {
545 if (wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) {
546 wd_readw(pTimer->regs + WD_DCNTR);
547 }
548 }
549
550 /* Stop a running watchdog timer-- the timer actually keeps
551 * running, but the interrupt is masked so that no action is
552 * taken upon expiration.
553 *
554 * pTimer - pointer to timer device
555 */
556 static void wd_stoptimer(struct wd_timer* pTimer)
557 {
558 if(wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) {
559 wd_toggleintr(pTimer, WD_INTR_OFF);
560
561 if(wd_dev.isbaddoggie) {
562 pTimer->runstatus |= WD_STAT_BSTOP;
563 wd_brokentimer((unsigned long)&wd_dev);
564 }
565 }
566 }
567
568 /* Start a watchdog timer with the specified limit value
569 * If the watchdog is running, it will be restarted with
570 * the provided limit value.
571 *
572 * This function will enable interrupts on the specified
573 * watchdog.
574 *
575 * pTimer - pointer to timer device
576 * limit - limit (countdown) value in 1/10th seconds
577 */
578 static void wd_starttimer(struct wd_timer* pTimer)
579 {
580 if(wd_dev.isbaddoggie) {
581 pTimer->runstatus &= ~WD_STAT_BSTOP;
582 }
583 pTimer->runstatus &= ~WD_STAT_SVCD;
584
585 wd_writew(pTimer->timeout, pTimer->regs + WD_LIMIT);
586 wd_toggleintr(pTimer, WD_INTR_ON);
587 }
588
589 /* Restarts timer with maximum limit value and
590 * does not unset 'brokenstop' value.
591 */
592 static void wd_resetbrokentimer(struct wd_timer* pTimer)
593 {
594 wd_toggleintr(pTimer, WD_INTR_ON);
595 wd_writew(WD_BLIMIT, pTimer->regs + WD_LIMIT);
596 }
597
598 /* Timer device initialization helper.
599 * Returns 0 on success, other on failure
600 */
601 static int wd_inittimer(int whichdog)
602 {
603 struct miscdevice *whichmisc;
604 void __iomem *whichregs;
605 char whichident[8];
606 int whichmask;
607 __u16 whichlimit;
608
609 switch(whichdog)
610 {
611 case WD0_ID:
612 whichmisc = &wd0_miscdev;
613 strcpy(whichident, "RIC");
614 whichregs = wd_dev.regs + WD0_OFF;
615 whichmask = WD0_INTR_MASK;
616 whichlimit= (0 == wd0_timeout) ?
617 (wd_dev.opt_timeout):
618 (wd0_timeout);
619 break;
620 case WD1_ID:
621 whichmisc = &wd1_miscdev;
622 strcpy(whichident, "XIR");
623 whichregs = wd_dev.regs + WD1_OFF;
624 whichmask = WD1_INTR_MASK;
625 whichlimit= (0 == wd1_timeout) ?
626 (wd_dev.opt_timeout):
627 (wd1_timeout);
628 break;
629 case WD2_ID:
630 whichmisc = &wd2_miscdev;
631 strcpy(whichident, "POR");
632 whichregs = wd_dev.regs + WD2_OFF;
633 whichmask = WD2_INTR_MASK;
634 whichlimit= (0 == wd2_timeout) ?
635 (wd_dev.opt_timeout):
636 (wd2_timeout);
637 break;
638 default:
639 printk("%s: %s: invalid watchdog id: %i\n",
640 WD_OBPNAME, __FUNCTION__, whichdog);
641 return(1);
642 }
643 if(0 != misc_register(whichmisc))
644 {
645 return(1);
646 }
647 wd_dev.watchdog[whichdog].regs = whichregs;
648 wd_dev.watchdog[whichdog].timeout = whichlimit;
649 wd_dev.watchdog[whichdog].intr_mask = whichmask;
650 wd_dev.watchdog[whichdog].runstatus &= ~WD_STAT_BSTOP;
651 wd_dev.watchdog[whichdog].runstatus |= WD_STAT_INIT;
652
653 printk("%s%i: %s hardware watchdog [%01i.%i sec] %s\n",
654 WD_OBPNAME,
655 whichdog,
656 whichident,
657 wd_dev.watchdog[whichdog].timeout / 10,
658 wd_dev.watchdog[whichdog].timeout % 10,
659 (0 != wd_dev.opt_enable) ? "in ENABLED mode" : "");
660 return(0);
661 }
662
663 /* Timer method called to reset stopped watchdogs--
664 * because of the PLD bug on CP1400, we cannot mask
665 * interrupts within the PLD so me must continually
666 * reset the timers ad infinitum.
667 */
668 static void wd_brokentimer(unsigned long data)
669 {
670 struct wd_device* pDev = (struct wd_device*)data;
671 int id, tripped = 0;
672
673 /* kill a running timer instance, in case we
674 * were called directly instead of by kernel timer
675 */
676 if(timer_pending(&wd_timer)) {
677 del_timer(&wd_timer);
678 }
679
680 for(id = WD0_ID; id < WD_NUMDEVS; ++id) {
681 if(pDev->watchdog[id].runstatus & WD_STAT_BSTOP) {
682 ++tripped;
683 wd_resetbrokentimer(&pDev->watchdog[id]);
684 }
685 }
686
687 if(tripped) {
688 /* there is at least one timer brokenstopped-- reschedule */
689 init_timer(&wd_timer);
690 wd_timer.expires = WD_BTIMEOUT;
691 add_timer(&wd_timer);
692 }
693 }
694
695 static int wd_getstatus(struct wd_timer* pTimer)
696 {
697 unsigned char stat = wd_readb(pTimer->regs + WD_STATUS);
698 unsigned char intr = wd_readb(wd_dev.regs + PLD_IMASK);
699 unsigned char ret = WD_STOPPED;
700
701 /* determine STOPPED */
702 if(0 == stat ) {
703 return(ret);
704 }
705 /* determine EXPIRED vs FREERUN vs RUNNING */
706 else if(WD_S_EXPIRED & stat) {
707 ret = WD_EXPIRED;
708 }
709 else if(WD_S_RUNNING & stat) {
710 if(intr & pTimer->intr_mask) {
711 ret = WD_FREERUN;
712 }
713 else {
714 /* Fudge WD_EXPIRED status for defective CP1400--
715 * IF timer is running
716 * AND brokenstop is set
717 * AND an interrupt has been serviced
718 * we are WD_EXPIRED.
719 *
720 * IF timer is running
721 * AND brokenstop is set
722 * AND no interrupt has been serviced
723 * we are WD_FREERUN.
724 */
725 if(wd_dev.isbaddoggie && (pTimer->runstatus & WD_STAT_BSTOP)) {
726 if(pTimer->runstatus & WD_STAT_SVCD) {
727 ret = WD_EXPIRED;
728 }
729 else {
730 /* we could as well pretend we are expired */
731 ret = WD_FREERUN;
732 }
733 }
734 else {
735 ret = WD_RUNNING;
736 }
737 }
738 }
739
740 /* determine SERVICED */
741 if(pTimer->runstatus & WD_STAT_SVCD) {
742 ret |= WD_SERVICED;
743 }
744
745 return(ret);
746 }
747
748 static int __init wd_init(void)
749 {
750 int id;
751 struct linux_ebus *ebus = NULL;
752 struct linux_ebus_device *edev = NULL;
753
754 for_each_ebus(ebus) {
755 for_each_ebusdev(edev, ebus) {
756 if (!strcmp(edev->ofdev.node->name, WD_OBPNAME))
757 goto ebus_done;
758 }
759 }
760
761 ebus_done:
762 if(!edev) {
763 printk("%s: unable to locate device\n", WD_OBPNAME);
764 return -ENODEV;
765 }
766
767 wd_dev.regs =
768 ioremap(edev->resource[0].start, 4 * WD_TIMER_REGSZ); /* ? */
769
770 if(NULL == wd_dev.regs) {
771 printk("%s: unable to map registers\n", WD_OBPNAME);
772 return(-ENODEV);
773 }
774
775 /* initialize device structure from OBP parameters */
776 wd_dev.irq = edev->irqs[0];
777 wd_dev.opt_enable = wd_opt_enable();
778 wd_dev.opt_reboot = wd_opt_reboot();
779 wd_dev.opt_timeout = wd_opt_timeout();
780 wd_dev.isbaddoggie = wd_isbroken();
781
782 /* disable all interrupts unless watchdog-enabled? == true */
783 if(! wd_dev.opt_enable) {
784 wd_toggleintr(NULL, WD_INTR_OFF);
785 }
786
787 /* register miscellaneous devices */
788 for(id = WD0_ID; id < WD_NUMDEVS; ++id) {
789 if(0 != wd_inittimer(id)) {
790 printk("%s%i: unable to initialize\n", WD_OBPNAME, id);
791 }
792 }
793
794 /* warn about possible defective PLD */
795 if(wd_dev.isbaddoggie) {
796 init_timer(&wd_timer);
797 wd_timer.function = wd_brokentimer;
798 wd_timer.data = (unsigned long)&wd_dev;
799 wd_timer.expires = WD_BTIMEOUT;
800
801 printk("%s: PLD defect workaround enabled for model %s\n",
802 WD_OBPNAME, WD_BADMODEL);
803 }
804 return(0);
805 }
806
807 static void __exit wd_cleanup(void)
808 {
809 int id;
810
811 /* if 'watchdog-enable?' == TRUE, timers are not stopped
812 * when module is unloaded. All brokenstopped timers will
813 * also now eventually trip.
814 */
815 for(id = WD0_ID; id < WD_NUMDEVS; ++id) {
816 if(WD_S_RUNNING == wd_readb(wd_dev.watchdog[id].regs + WD_STATUS)) {
817 if(wd_dev.opt_enable) {
818 printk(KERN_WARNING "%s%i: timer not stopped at release\n",
819 WD_OBPNAME, id);
820 }
821 else {
822 wd_stoptimer(&wd_dev.watchdog[id]);
823 if(wd_dev.watchdog[id].runstatus & WD_STAT_BSTOP) {
824 wd_resetbrokentimer(&wd_dev.watchdog[id]);
825 printk(KERN_WARNING
826 "%s%i: defect workaround disabled at release, "\
827 "timer expires in ~%01i sec\n",
828 WD_OBPNAME, id,
829 wd_readw(wd_dev.watchdog[id].regs + WD_LIMIT) / 10);
830 }
831 }
832 }
833 }
834
835 if(wd_dev.isbaddoggie && timer_pending(&wd_timer)) {
836 del_timer(&wd_timer);
837 }
838 if(0 != (wd_dev.watchdog[WD0_ID].runstatus & WD_STAT_INIT)) {
839 misc_deregister(&wd0_miscdev);
840 }
841 if(0 != (wd_dev.watchdog[WD1_ID].runstatus & WD_STAT_INIT)) {
842 misc_deregister(&wd1_miscdev);
843 }
844 if(0 != (wd_dev.watchdog[WD2_ID].runstatus & WD_STAT_INIT)) {
845 misc_deregister(&wd2_miscdev);
846 }
847 if(0 != wd_dev.initialized) {
848 free_irq(wd_dev.irq, (void *)wd_dev.regs);
849 }
850 iounmap(wd_dev.regs);
851 }
852
853 module_init(wd_init);
854 module_exit(wd_cleanup);
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