[SPARC] cpwatchdog: implement ->compat_ioctl
[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  * 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                                                 SA_SHIRQ,
305                                                 WD_OBPNAME,
306                                                 (void *)wd_dev.regs)) {
307                         printk("%s: Cannot register IRQ %s\n", 
308                                 WD_OBPNAME, __irq_itoa(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                 lock_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->prom_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);