[PATCH 13/13] drivers/watchdog: use USB API functions rather than constants
[linux-2.6.git] / drivers / watchdog / cpwd.c
1 /* cpwd.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  * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
15  */
16
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/fs.h>
20 #include <linux/errno.h>
21 #include <linux/major.h>
22 #include <linux/init.h>
23 #include <linux/miscdevice.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioport.h>
26 #include <linux/timer.h>
27 #include <linux/smp_lock.h>
28 #include <linux/io.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31
32 #include <asm/irq.h>
33 #include <asm/uaccess.h>
34
35 #include <asm/watchdog.h>
36
37 #define DRIVER_NAME     "cpwd"
38 #define PFX             DRIVER_NAME ": "
39
40 #define WD_OBPNAME      "watchdog"
41 #define WD_BADMODEL     "SUNW,501-5336"
42 #define WD_BTIMEOUT     (jiffies + (HZ * 1000))
43 #define WD_BLIMIT       0xFFFF
44
45 #define WD0_MINOR       212
46 #define WD1_MINOR       213     
47 #define WD2_MINOR       214     
48
49 /* Internal driver definitions.  */
50 #define WD0_ID                  0
51 #define WD1_ID                  1
52 #define WD2_ID                  2
53 #define WD_NUMDEVS              3
54
55 #define WD_INTR_OFF             0
56 #define WD_INTR_ON              1
57
58 #define WD_STAT_INIT    0x01    /* Watchdog timer is initialized        */
59 #define WD_STAT_BSTOP   0x02    /* Watchdog timer is brokenstopped      */
60 #define WD_STAT_SVCD    0x04    /* Watchdog interrupt occurred          */
61
62 /* Register value definitions
63  */
64 #define WD0_INTR_MASK   0x01    /* Watchdog device interrupt masks      */
65 #define WD1_INTR_MASK   0x02
66 #define WD2_INTR_MASK   0x04
67
68 #define WD_S_RUNNING    0x01    /* Watchdog device status running       */
69 #define WD_S_EXPIRED    0x02    /* Watchdog device status expired       */
70
71 struct cpwd {
72         void __iomem    *regs;
73         spinlock_t      lock;
74
75         unsigned int    irq;
76
77         unsigned long   timeout;
78         bool            enabled;
79         bool            reboot;
80         bool            broken;
81         bool            initialized;
82
83         struct {
84                 struct miscdevice       misc;
85                 void __iomem            *regs;
86                 u8                      intr_mask;
87                 u8                      runstatus;
88                 u16                     timeout;
89         } devs[WD_NUMDEVS];
90 };
91
92 static struct cpwd *cpwd_device;
93
94 /* Sun uses Altera PLD EPF8820ATC144-4 
95  * providing three hardware watchdogs:
96  *
97  *      1) RIC - sends an interrupt when triggered
98  *      2) XIR - asserts XIR_B_RESET when triggered, resets CPU
99  *      3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board
100  *
101  *** Timer register block definition (struct wd_timer_regblk)
102  *
103  * dcntr and limit registers (halfword access):      
104  * -------------------
105  * | 15 | ...| 1 | 0 |
106  * -------------------
107  * |-  counter val  -|
108  * -------------------
109  * dcntr -      Current 16-bit downcounter value.
110  *                      When downcounter reaches '0' watchdog expires.
111  *                      Reading this register resets downcounter with 'limit' value.
112  * limit -      16-bit countdown value in 1/10th second increments.
113  *                      Writing this register begins countdown with input value.
114  *                      Reading from this register does not affect counter.
115  * NOTES:       After watchdog reset, dcntr and limit contain '1'
116  *
117  * status register (byte access):
118  * ---------------------------
119  * | 7 | ... | 2 |  1  |  0  |
120  * --------------+------------
121  * |-   UNUSED  -| EXP | RUN |
122  * ---------------------------
123  * status-      Bit 0 - Watchdog is running
124  *                      Bit 1 - Watchdog has expired
125  *
126  *** PLD register block definition (struct wd_pld_regblk)
127  *
128  * intr_mask register (byte access):
129  * ---------------------------------
130  * | 7 | ... | 3 |  2  |  1  |  0  |
131  * +-------------+------------------
132  * |-   UNUSED  -| WD3 | WD2 | WD1 |
133  * ---------------------------------
134  * WD3 -  1 == Interrupt disabled for watchdog 3
135  * WD2 -  1 == Interrupt disabled for watchdog 2
136  * WD1 -  1 == Interrupt disabled for watchdog 1
137  *
138  * pld_status register (byte access):
139  * UNKNOWN, MAGICAL MYSTERY REGISTER
140  *
141  */
142 #define WD_TIMER_REGSZ  16
143 #define WD0_OFF         0
144 #define WD1_OFF         (WD_TIMER_REGSZ * 1)
145 #define WD2_OFF         (WD_TIMER_REGSZ * 2)
146 #define PLD_OFF         (WD_TIMER_REGSZ * 3)
147
148 #define WD_DCNTR        0x00
149 #define WD_LIMIT        0x04
150 #define WD_STATUS       0x08
151
152 #define PLD_IMASK       (PLD_OFF + 0x00)
153 #define PLD_STATUS      (PLD_OFF + 0x04)
154
155 static struct timer_list cpwd_timer;
156
157 static int wd0_timeout = 0;
158 static int wd1_timeout = 0;
159 static int wd2_timeout = 0;
160
161 module_param    (wd0_timeout, int, 0);
162 MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
163 module_param    (wd1_timeout, int, 0);
164 MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
165 module_param    (wd2_timeout, int, 0);
166 MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs");
167
168 MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
169 MODULE_DESCRIPTION("Hardware watchdog driver for Sun Microsystems CP1400/1500");
170 MODULE_LICENSE("GPL");
171 MODULE_SUPPORTED_DEVICE("watchdog");
172
173 static void cpwd_writew(u16 val, void __iomem *addr)
174 {
175         writew(cpu_to_le16(val), addr);
176 }
177 static u16 cpwd_readw(void __iomem *addr)
178 {
179         u16 val = readw(addr);
180
181         return le16_to_cpu(val);
182 }
183
184 static void cpwd_writeb(u8 val, void __iomem *addr)
185 {
186         writeb(val, addr);
187 }
188
189 static u8 cpwd_readb(void __iomem *addr)
190 {
191         return readb(addr);
192 }
193
194 /* Enable or disable watchdog interrupts
195  * Because of the CP1400 defect this should only be
196  * called during initialzation or by wd_[start|stop]timer()
197  *
198  * index        - sub-device index, or -1 for 'all'
199  * enable       - non-zero to enable interrupts, zero to disable
200  */
201 static void cpwd_toggleintr(struct cpwd *p, int index, int enable)
202 {
203         unsigned char curregs = cpwd_readb(p->regs + PLD_IMASK);
204         unsigned char setregs = 
205                 (index == -1) ? 
206                 (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : 
207                 (p->devs[index].intr_mask);
208
209         if (enable == WD_INTR_ON)
210                 curregs &= ~setregs;
211         else
212                 curregs |= setregs;
213
214         cpwd_writeb(curregs, p->regs + PLD_IMASK);
215 }
216
217 /* Restarts timer with maximum limit value and
218  * does not unset 'brokenstop' value.
219  */
220 static void cpwd_resetbrokentimer(struct cpwd *p, int index)
221 {
222         cpwd_toggleintr(p, index, WD_INTR_ON);
223         cpwd_writew(WD_BLIMIT, p->devs[index].regs + WD_LIMIT);
224 }
225
226 /* Timer method called to reset stopped watchdogs--
227  * because of the PLD bug on CP1400, we cannot mask
228  * interrupts within the PLD so me must continually
229  * reset the timers ad infinitum.
230  */
231 static void cpwd_brokentimer(unsigned long data)
232 {
233         struct cpwd *p = (struct cpwd *) data;
234         int id, tripped = 0;
235
236         /* kill a running timer instance, in case we
237          * were called directly instead of by kernel timer
238          */
239         if (timer_pending(&cpwd_timer))
240                 del_timer(&cpwd_timer);
241
242         for (id = 0; id < WD_NUMDEVS; id++) {
243                 if (p->devs[id].runstatus & WD_STAT_BSTOP) {
244                         ++tripped;
245                         cpwd_resetbrokentimer(p, id);
246                 }
247         }
248
249         if (tripped) {
250                 /* there is at least one timer brokenstopped-- reschedule */
251                 cpwd_timer.expires = WD_BTIMEOUT;
252                 add_timer(&cpwd_timer);
253         }
254 }
255
256 /* Reset countdown timer with 'limit' value and continue countdown.
257  * This will not start a stopped timer.
258  */
259 static void cpwd_pingtimer(struct cpwd *p, int index)
260 {
261         if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING)
262                 cpwd_readw(p->devs[index].regs + WD_DCNTR);
263 }
264
265 /* Stop a running watchdog timer-- the timer actually keeps
266  * running, but the interrupt is masked so that no action is
267  * taken upon expiration.
268  */
269 static void cpwd_stoptimer(struct cpwd *p, int index)
270 {
271         if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) {
272                 cpwd_toggleintr(p, index, WD_INTR_OFF);
273
274                 if (p->broken) {
275                         p->devs[index].runstatus |= WD_STAT_BSTOP;
276                         cpwd_brokentimer((unsigned long) p);
277                 }
278         }
279 }
280
281 /* Start a watchdog timer with the specified limit value
282  * If the watchdog is running, it will be restarted with
283  * the provided limit value.
284  *
285  * This function will enable interrupts on the specified
286  * watchdog.
287  */
288 static void cpwd_starttimer(struct cpwd *p, int index)
289 {
290         if (p->broken)
291                 p->devs[index].runstatus &= ~WD_STAT_BSTOP;
292
293         p->devs[index].runstatus &= ~WD_STAT_SVCD;
294
295         cpwd_writew(p->devs[index].timeout, p->devs[index].regs + WD_LIMIT);
296         cpwd_toggleintr(p, index, WD_INTR_ON);
297 }
298
299 static int cpwd_getstatus(struct cpwd *p, int index)
300 {
301         unsigned char stat = cpwd_readb(p->devs[index].regs + WD_STATUS);
302         unsigned char intr = cpwd_readb(p->devs[index].regs + PLD_IMASK);
303         unsigned char ret  = WD_STOPPED;
304
305         /* determine STOPPED */
306         if (!stat) 
307                 return ret;
308
309         /* determine EXPIRED vs FREERUN vs RUNNING */
310         else if (WD_S_EXPIRED & stat) {
311                 ret = WD_EXPIRED;
312         } else if(WD_S_RUNNING & stat) {
313                 if (intr & p->devs[index].intr_mask) {
314                         ret = WD_FREERUN;
315                 } else {
316                         /* Fudge WD_EXPIRED status for defective CP1400--
317                          * IF timer is running 
318                          *      AND brokenstop is set 
319                          *      AND an interrupt has been serviced
320                          * we are WD_EXPIRED.
321                          *
322                          * IF timer is running 
323                          *      AND brokenstop is set 
324                          *      AND no interrupt has been serviced
325                          * we are WD_FREERUN.
326                          */
327                         if (p->broken &&
328                             (p->devs[index].runstatus & WD_STAT_BSTOP)) {
329                                 if (p->devs[index].runstatus & WD_STAT_SVCD) {
330                                         ret = WD_EXPIRED;
331                                 } else {
332                                         /* we could as well pretend we are expired */
333                                         ret = WD_FREERUN;
334                                 }
335                         } else {
336                                 ret = WD_RUNNING;
337                         }
338                 }
339         }
340
341         /* determine SERVICED */
342         if (p->devs[index].runstatus & WD_STAT_SVCD)
343                 ret |= WD_SERVICED;
344
345         return(ret);
346 }
347
348 static irqreturn_t cpwd_interrupt(int irq, void *dev_id)
349 {
350         struct cpwd *p = dev_id;
351
352         /* Only WD0 will interrupt-- others are NMI and we won't
353          * see them here....
354          */
355         spin_lock_irq(&p->lock);
356
357         cpwd_stoptimer(p, WD0_ID);
358         p->devs[WD0_ID].runstatus |=  WD_STAT_SVCD;
359
360         spin_unlock_irq(&p->lock);
361
362         return IRQ_HANDLED;
363 }
364
365 static int cpwd_open(struct inode *inode, struct file *f)
366 {
367         struct cpwd *p = cpwd_device;
368
369         lock_kernel();
370         switch(iminor(inode)) {
371                 case WD0_MINOR:
372                 case WD1_MINOR:
373                 case WD2_MINOR:
374                         break;
375
376                 default:
377                         unlock_kernel();
378                         return -ENODEV;
379         }
380
381         /* Register IRQ on first open of device */
382         if (!p->initialized) {
383                 if (request_irq(p->irq, &cpwd_interrupt, 
384                                 IRQF_SHARED, DRIVER_NAME, p)) {
385                         printk(KERN_ERR PFX "Cannot register IRQ %d\n", 
386                                 p->irq);
387                         unlock_kernel();
388                         return -EBUSY;
389                 }
390                 p->initialized = true;
391         }
392
393         unlock_kernel();
394
395         return nonseekable_open(inode, f);
396 }
397
398 static int cpwd_release(struct inode *inode, struct file *file)
399 {
400         return 0;
401 }
402
403 static long cpwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
404 {
405         static struct watchdog_info info = {
406                 .options                = WDIOF_SETTIMEOUT,
407                 .firmware_version       = 1,
408                 .identity               = DRIVER_NAME,
409         };
410         void __user *argp = (void __user *)arg;
411         struct inode *inode = file->f_path.dentry->d_inode;
412         int index = iminor(inode) - WD0_MINOR;
413         struct cpwd *p = cpwd_device;
414         int setopt = 0;
415
416         switch (cmd) {
417         /* Generic Linux IOCTLs */
418         case WDIOC_GETSUPPORT:
419                 if (copy_to_user(argp, &info, sizeof(struct watchdog_info)))
420                         return -EFAULT;
421                 break;
422
423         case WDIOC_GETSTATUS:
424         case WDIOC_GETBOOTSTATUS:
425                 if (put_user(0, (int __user *)argp))
426                         return -EFAULT;
427                 break;
428
429         case WDIOC_KEEPALIVE:
430                 cpwd_pingtimer(p, index);
431                 break;
432
433         case WDIOC_SETOPTIONS:
434                 if (copy_from_user(&setopt, argp, sizeof(unsigned int)))
435                         return -EFAULT;
436
437                 if (setopt & WDIOS_DISABLECARD) {
438                         if (p->enabled)
439                                 return -EINVAL;
440                         cpwd_stoptimer(p, index);
441                 } else if (setopt & WDIOS_ENABLECARD) {
442                         cpwd_starttimer(p, index);
443                 } else {
444                         return -EINVAL;
445                 }       
446                 break;
447
448         /* Solaris-compatible IOCTLs */
449         case WIOCGSTAT:
450                 setopt = cpwd_getstatus(p, index);
451                 if (copy_to_user(argp, &setopt, sizeof(unsigned int)))
452                         return -EFAULT;
453                 break;
454
455         case WIOCSTART:
456                 cpwd_starttimer(p, index);
457                 break;
458
459         case WIOCSTOP:
460                 if (p->enabled)
461                         return(-EINVAL);
462
463                 cpwd_stoptimer(p, index);
464                 break;
465
466         default:
467                 return -EINVAL;
468         }
469
470         return 0;
471 }
472
473 static long cpwd_compat_ioctl(struct file *file, unsigned int cmd,
474                               unsigned long arg)
475 {
476         int rval = -ENOIOCTLCMD;
477
478         switch (cmd) {
479         /* solaris ioctls are specific to this driver */
480         case WIOCSTART:
481         case WIOCSTOP:
482         case WIOCGSTAT:
483                 lock_kernel();
484                 rval = cpwd_ioctl(file, cmd, arg);
485                 unlock_kernel();
486                 break;
487
488         /* everything else is handled by the generic compat layer */
489         default:
490                 break;
491         }
492
493         return rval;
494 }
495
496 static ssize_t cpwd_write(struct file *file, const char __user *buf, 
497                           size_t count, loff_t *ppos)
498 {
499         struct inode *inode = file->f_path.dentry->d_inode;
500         struct cpwd *p = cpwd_device;
501         int index = iminor(inode);
502
503         if (count) {
504                 cpwd_pingtimer(p, index);
505                 return 1;
506         }
507
508         return 0;
509 }
510
511 static ssize_t cpwd_read(struct file * file, char __user *buffer,
512                          size_t count, loff_t *ppos)
513 {
514         return -EINVAL;
515 }
516
517 static const struct file_operations cpwd_fops = {
518         .owner =                THIS_MODULE,
519         .unlocked_ioctl =       cpwd_ioctl,
520         .compat_ioctl =         cpwd_compat_ioctl,
521         .open =                 cpwd_open,
522         .write =                cpwd_write,
523         .read =                 cpwd_read,
524         .release =              cpwd_release,
525 };
526
527 static int __devinit cpwd_probe(struct of_device *op,
528                                 const struct of_device_id *match)
529 {
530         struct device_node *options;
531         const char *str_prop;
532         const void *prop_val;
533         int i, err = -EINVAL;
534         struct cpwd *p;
535
536         if (cpwd_device)
537                 return -EINVAL;
538
539         p = kzalloc(sizeof(*p), GFP_KERNEL);
540         err = -ENOMEM;
541         if (!p) {
542                 printk(KERN_ERR PFX "Unable to allocate struct cpwd.\n");
543                 goto out;
544         }
545
546         p->irq = op->irqs[0];
547
548         spin_lock_init(&p->lock);
549
550         p->regs = of_ioremap(&op->resource[0], 0,
551                              4 * WD_TIMER_REGSZ, DRIVER_NAME);
552         if (!p->regs) {
553                 printk(KERN_ERR PFX "Unable to map registers.\n");
554                 goto out_free;
555         }
556
557         options = of_find_node_by_path("/options");
558         err = -ENODEV;
559         if (!options) {
560                 printk(KERN_ERR PFX "Unable to find /options node.\n");
561                 goto out_iounmap;
562         }
563
564         prop_val = of_get_property(options, "watchdog-enable?", NULL);
565         p->enabled = (prop_val ? true : false);
566
567         prop_val = of_get_property(options, "watchdog-reboot?", NULL);
568         p->reboot = (prop_val ? true : false);
569
570         str_prop = of_get_property(options, "watchdog-timeout", NULL);
571         if (str_prop)
572                 p->timeout = simple_strtoul(str_prop, NULL, 10);
573
574         /* CP1400s seem to have broken PLD implementations-- the
575          * interrupt_mask register cannot be written, so no timer
576          * interrupts can be masked within the PLD.
577          */
578         str_prop = of_get_property(op->node, "model", NULL);
579         p->broken = (str_prop && !strcmp(str_prop, WD_BADMODEL));
580
581         if (!p->enabled)
582                 cpwd_toggleintr(p, -1, WD_INTR_OFF);
583
584         for (i = 0; i < WD_NUMDEVS; i++) {
585                 static const char *cpwd_names[] = { "RIC", "XIR", "POR" };
586                 static int *parms[] = { &wd0_timeout,
587                                         &wd1_timeout,
588                                         &wd2_timeout };
589                 struct miscdevice *mp = &p->devs[i].misc;
590
591                 mp->minor = WD0_MINOR + i;
592                 mp->name = cpwd_names[i];
593                 mp->fops = &cpwd_fops;
594
595                 p->devs[i].regs = p->regs + (i * WD_TIMER_REGSZ);
596                 p->devs[i].intr_mask = (WD0_INTR_MASK << i);
597                 p->devs[i].runstatus &= ~WD_STAT_BSTOP;
598                 p->devs[i].runstatus |= WD_STAT_INIT;
599                 p->devs[i].timeout = p->timeout;
600                 if (*parms[i])
601                         p->devs[i].timeout = *parms[i];
602
603                 err = misc_register(&p->devs[i].misc);
604                 if (err) {
605                         printk(KERN_ERR "Could not register misc device for "
606                                "dev %d\n", i);
607                         goto out_unregister;
608                 }
609         }
610
611         if (p->broken) {
612                 init_timer(&cpwd_timer);
613                 cpwd_timer.function     = cpwd_brokentimer;
614                 cpwd_timer.data         = (unsigned long) p;
615                 cpwd_timer.expires      = WD_BTIMEOUT;
616
617                 printk(KERN_INFO PFX "PLD defect workaround enabled for "
618                        "model " WD_BADMODEL ".\n");
619         }
620
621         dev_set_drvdata(&op->dev, p);
622         cpwd_device = p;
623         err = 0;
624
625 out:
626         return err;
627
628 out_unregister:
629         for (i--; i >= 0; i--)
630                 misc_deregister(&p->devs[i].misc);
631
632 out_iounmap:
633         of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
634
635 out_free:
636         kfree(p);
637         goto out;
638 }
639
640 static int __devexit cpwd_remove(struct of_device *op)
641 {
642         struct cpwd *p = dev_get_drvdata(&op->dev);
643         int i;
644
645         for (i = 0; i < 4; i++) {
646                 misc_deregister(&p->devs[i].misc);
647
648                 if (!p->enabled) {
649                         cpwd_stoptimer(p, i);
650                         if (p->devs[i].runstatus & WD_STAT_BSTOP)
651                                 cpwd_resetbrokentimer(p, i);
652                 }
653         }
654
655         if (p->broken)
656                 del_timer_sync(&cpwd_timer);
657
658         if (p->initialized)
659                 free_irq(p->irq, p);
660
661         of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
662         kfree(p);
663
664         cpwd_device = NULL;
665
666         return 0;
667 }
668
669 static const struct of_device_id cpwd_match[] = {
670         {
671                 .name = "watchdog",
672         },
673         {},
674 };
675 MODULE_DEVICE_TABLE(of, cpwd_match);
676
677 static struct of_platform_driver cpwd_driver = {
678         .name           = DRIVER_NAME,
679         .match_table    = cpwd_match,
680         .probe          = cpwd_probe,
681         .remove         = __devexit_p(cpwd_remove),
682 };
683
684 static int __init cpwd_init(void)
685 {
686         return of_register_driver(&cpwd_driver, &of_bus_type);
687 }
688
689 static void __exit cpwd_exit(void)
690 {
691         of_unregister_driver(&cpwd_driver);
692 }
693
694 module_init(cpwd_init);
695 module_exit(cpwd_exit);