drivers: replace remaining __FUNCTION__ occurrences
[linux-2.6.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  * 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/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/timer.h>
26 #include <linux/smp_lock.h>
27 #include <linux/io.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(wd_dev.lock), 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);
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_path.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)
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 const 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, __func__, 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);