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