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1da177e4 LT |
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 <asm/irq.h> | |
30 | #include <asm/ebus.h> | |
31 | #include <asm/oplib.h> | |
32 | #include <asm/uaccess.h> | |
33 | ||
34 | #include <asm/watchdog.h> | |
35 | ||
36 | #define WD_OBPNAME "watchdog" | |
37 | #define WD_BADMODEL "SUNW,501-5336" | |
38 | #define WD_BTIMEOUT (jiffies + (HZ * 1000)) | |
39 | #define WD_BLIMIT 0xFFFF | |
40 | ||
41 | #define WD0_DEVNAME "watchdog0" | |
42 | #define WD1_DEVNAME "watchdog1" | |
43 | #define WD2_DEVNAME "watchdog2" | |
44 | ||
45 | #define WD0_MINOR 212 | |
46 | #define WD1_MINOR 213 | |
47 | #define WD2_MINOR 214 | |
48 | ||
49 | ||
50 | /* Internal driver definitions | |
51 | */ | |
52 | #define WD0_ID 0 /* Watchdog0 */ | |
53 | #define WD1_ID 1 /* Watchdog1 */ | |
54 | #define WD2_ID 2 /* Watchdog2 */ | |
55 | #define WD_NUMDEVS 3 /* Device contains 3 timers */ | |
56 | ||
57 | #define WD_INTR_OFF 0 /* Interrupt disable value */ | |
58 | #define WD_INTR_ON 1 /* Interrupt enable value */ | |
59 | ||
60 | #define WD_STAT_INIT 0x01 /* Watchdog timer is initialized */ | |
61 | #define WD_STAT_BSTOP 0x02 /* Watchdog timer is brokenstopped */ | |
62 | #define WD_STAT_SVCD 0x04 /* Watchdog interrupt occurred */ | |
63 | ||
64 | /* Register value definitions | |
65 | */ | |
66 | #define WD0_INTR_MASK 0x01 /* Watchdog device interrupt masks */ | |
67 | #define WD1_INTR_MASK 0x02 | |
68 | #define WD2_INTR_MASK 0x04 | |
69 | ||
70 | #define WD_S_RUNNING 0x01 /* Watchdog device status running */ | |
71 | #define WD_S_EXPIRED 0x02 /* Watchdog device status expired */ | |
72 | ||
73 | /* Sun uses Altera PLD EPF8820ATC144-4 | |
74 | * providing three hardware watchdogs: | |
75 | * | |
76 | * 1) RIC - sends an interrupt when triggered | |
77 | * 2) XIR - asserts XIR_B_RESET when triggered, resets CPU | |
78 | * 3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board | |
79 | * | |
80 | *** Timer register block definition (struct wd_timer_regblk) | |
81 | * | |
82 | * dcntr and limit registers (halfword access): | |
83 | * ------------------- | |
84 | * | 15 | ...| 1 | 0 | | |
85 | * ------------------- | |
86 | * |- counter val -| | |
87 | * ------------------- | |
88 | * dcntr - Current 16-bit downcounter value. | |
89 | * When downcounter reaches '0' watchdog expires. | |
90 | * Reading this register resets downcounter with 'limit' value. | |
91 | * limit - 16-bit countdown value in 1/10th second increments. | |
92 | * Writing this register begins countdown with input value. | |
93 | * Reading from this register does not affect counter. | |
94 | * NOTES: After watchdog reset, dcntr and limit contain '1' | |
95 | * | |
96 | * status register (byte access): | |
97 | * --------------------------- | |
98 | * | 7 | ... | 2 | 1 | 0 | | |
99 | * --------------+------------ | |
100 | * |- UNUSED -| EXP | RUN | | |
101 | * --------------------------- | |
102 | * status- Bit 0 - Watchdog is running | |
103 | * Bit 1 - Watchdog has expired | |
104 | * | |
105 | *** PLD register block definition (struct wd_pld_regblk) | |
106 | * | |
107 | * intr_mask register (byte access): | |
108 | * --------------------------------- | |
109 | * | 7 | ... | 3 | 2 | 1 | 0 | | |
110 | * +-------------+------------------ | |
111 | * |- UNUSED -| WD3 | WD2 | WD1 | | |
112 | * --------------------------------- | |
113 | * WD3 - 1 == Interrupt disabled for watchdog 3 | |
114 | * WD2 - 1 == Interrupt disabled for watchdog 2 | |
115 | * WD1 - 1 == Interrupt disabled for watchdog 1 | |
116 | * | |
117 | * pld_status register (byte access): | |
118 | * UNKNOWN, MAGICAL MYSTERY REGISTER | |
119 | * | |
120 | */ | |
121 | #define WD_TIMER_REGSZ 16 | |
122 | #define WD0_OFF 0 | |
123 | #define WD1_OFF (WD_TIMER_REGSZ * 1) | |
124 | #define WD2_OFF (WD_TIMER_REGSZ * 2) | |
125 | #define PLD_OFF (WD_TIMER_REGSZ * 3) | |
126 | ||
127 | #define WD_DCNTR 0x00 | |
128 | #define WD_LIMIT 0x04 | |
129 | #define WD_STATUS 0x08 | |
130 | ||
131 | #define PLD_IMASK (PLD_OFF + 0x00) | |
132 | #define PLD_STATUS (PLD_OFF + 0x04) | |
133 | ||
134 | /* Individual timer structure | |
135 | */ | |
136 | struct wd_timer { | |
137 | __u16 timeout; | |
138 | __u8 intr_mask; | |
139 | unsigned char runstatus; | |
140 | void __iomem *regs; | |
141 | }; | |
142 | ||
143 | /* Device structure | |
144 | */ | |
145 | struct wd_device { | |
146 | int irq; | |
147 | spinlock_t lock; | |
148 | unsigned char isbaddoggie; /* defective PLD */ | |
149 | unsigned char opt_enable; | |
150 | unsigned char opt_reboot; | |
151 | unsigned short opt_timeout; | |
152 | unsigned char initialized; | |
153 | struct wd_timer watchdog[WD_NUMDEVS]; | |
154 | void __iomem *regs; | |
155 | }; | |
156 | ||
157 | static struct wd_device wd_dev = { | |
158 | 0, SPIN_LOCK_UNLOCKED, 0, 0, 0, 0, | |
159 | }; | |
160 | ||
161 | static struct timer_list wd_timer; | |
162 | ||
163 | static int wd0_timeout = 0; | |
164 | static int wd1_timeout = 0; | |
165 | static int wd2_timeout = 0; | |
166 | ||
167 | #ifdef MODULE | |
168 | module_param (wd0_timeout, int, 0); | |
169 | MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs"); | |
170 | module_param (wd1_timeout, int, 0); | |
171 | MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs"); | |
172 | module_param (wd2_timeout, int, 0); | |
173 | MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs"); | |
174 | ||
175 | MODULE_AUTHOR | |
176 | ("Eric Brower <ebrower@usa.net>"); | |
177 | MODULE_DESCRIPTION | |
178 | ("Hardware watchdog driver for Sun Microsystems CP1400/1500"); | |
179 | MODULE_LICENSE("GPL"); | |
180 | MODULE_SUPPORTED_DEVICE | |
181 | ("watchdog"); | |
182 | #endif /* ifdef MODULE */ | |
183 | ||
184 | /* Forward declarations of internal methods | |
185 | */ | |
186 | #ifdef WD_DEBUG | |
187 | static void wd_dumpregs(void); | |
188 | #endif | |
189 | static irqreturn_t wd_interrupt(int irq, void *dev_id, struct pt_regs *regs); | |
190 | static void wd_toggleintr(struct wd_timer* pTimer, int enable); | |
191 | static void wd_pingtimer(struct wd_timer* pTimer); | |
192 | static void wd_starttimer(struct wd_timer* pTimer); | |
193 | static void wd_resetbrokentimer(struct wd_timer* pTimer); | |
194 | static void wd_stoptimer(struct wd_timer* pTimer); | |
195 | static void wd_brokentimer(unsigned long data); | |
196 | static int wd_getstatus(struct wd_timer* pTimer); | |
197 | ||
198 | /* PLD expects words to be written in LSB format, | |
199 | * so we must flip all words prior to writing them to regs | |
200 | */ | |
201 | static inline unsigned short flip_word(unsigned short word) | |
202 | { | |
203 | return ((word & 0xff) << 8) | ((word >> 8) & 0xff); | |
204 | } | |
205 | ||
206 | #define wd_writew(val, addr) (writew(flip_word(val), addr)) | |
207 | #define wd_readw(addr) (flip_word(readw(addr))) | |
208 | #define wd_writeb(val, addr) (writeb(val, addr)) | |
209 | #define wd_readb(addr) (readb(addr)) | |
210 | ||
211 | ||
212 | /* CP1400s seem to have broken PLD implementations-- | |
213 | * the interrupt_mask register cannot be written, so | |
214 | * no timer interrupts can be masked within the PLD. | |
215 | */ | |
216 | static inline int wd_isbroken(void) | |
217 | { | |
218 | /* we could test this by read/write/read/restore | |
219 | * on the interrupt mask register only if OBP | |
220 | * 'watchdog-enable?' == FALSE, but it seems | |
221 | * ubiquitous on CP1400s | |
222 | */ | |
223 | char val[32]; | |
224 | prom_getproperty(prom_root_node, "model", val, sizeof(val)); | |
225 | return((!strcmp(val, WD_BADMODEL)) ? 1 : 0); | |
226 | } | |
227 | ||
228 | /* Retrieve watchdog-enable? option from OBP | |
229 | * Returns 0 if false, 1 if true | |
230 | */ | |
231 | static inline int wd_opt_enable(void) | |
232 | { | |
233 | int opt_node; | |
234 | ||
235 | opt_node = prom_getchild(prom_root_node); | |
236 | opt_node = prom_searchsiblings(opt_node, "options"); | |
237 | return((-1 == prom_getint(opt_node, "watchdog-enable?")) ? 0 : 1); | |
238 | } | |
239 | ||
240 | /* Retrieve watchdog-reboot? option from OBP | |
241 | * Returns 0 if false, 1 if true | |
242 | */ | |
243 | static inline int wd_opt_reboot(void) | |
244 | { | |
245 | int opt_node; | |
246 | ||
247 | opt_node = prom_getchild(prom_root_node); | |
248 | opt_node = prom_searchsiblings(opt_node, "options"); | |
249 | return((-1 == prom_getint(opt_node, "watchdog-reboot?")) ? 0 : 1); | |
250 | } | |
251 | ||
252 | /* Retrieve watchdog-timeout option from OBP | |
253 | * Returns OBP value, or 0 if not located | |
254 | */ | |
255 | static inline int wd_opt_timeout(void) | |
256 | { | |
257 | int opt_node; | |
258 | char value[32]; | |
259 | char *p = value; | |
260 | ||
261 | opt_node = prom_getchild(prom_root_node); | |
262 | opt_node = prom_searchsiblings(opt_node, "options"); | |
263 | opt_node = prom_getproperty(opt_node, | |
264 | "watchdog-timeout", | |
265 | value, | |
266 | sizeof(value)); | |
267 | if(-1 != opt_node) { | |
268 | /* atoi implementation */ | |
269 | for(opt_node = 0; /* nop */; p++) { | |
270 | if(*p >= '0' && *p <= '9') { | |
271 | opt_node = (10*opt_node)+(*p-'0'); | |
272 | } | |
273 | else { | |
274 | break; | |
275 | } | |
276 | } | |
277 | } | |
278 | return((-1 == opt_node) ? (0) : (opt_node)); | |
279 | } | |
280 | ||
281 | static int wd_open(struct inode *inode, struct file *f) | |
282 | { | |
283 | switch(iminor(inode)) | |
284 | { | |
285 | case WD0_MINOR: | |
286 | f->private_data = &wd_dev.watchdog[WD0_ID]; | |
287 | break; | |
288 | case WD1_MINOR: | |
289 | f->private_data = &wd_dev.watchdog[WD1_ID]; | |
290 | break; | |
291 | case WD2_MINOR: | |
292 | f->private_data = &wd_dev.watchdog[WD2_ID]; | |
293 | break; | |
294 | default: | |
295 | return(-ENODEV); | |
296 | } | |
297 | ||
298 | /* Register IRQ on first open of device */ | |
299 | if(0 == wd_dev.initialized) | |
300 | { | |
301 | if (request_irq(wd_dev.irq, | |
302 | &wd_interrupt, | |
303 | SA_SHIRQ, | |
304 | WD_OBPNAME, | |
305 | (void *)wd_dev.regs)) { | |
306 | printk("%s: Cannot register IRQ %s\n", | |
307 | WD_OBPNAME, __irq_itoa(wd_dev.irq)); | |
308 | return(-EBUSY); | |
309 | } | |
310 | wd_dev.initialized = 1; | |
311 | } | |
312 | ||
313 | return(nonseekable_open(inode, f)); | |
314 | } | |
315 | ||
316 | static int wd_release(struct inode *inode, struct file *file) | |
317 | { | |
318 | return 0; | |
319 | } | |
320 | ||
321 | static int wd_ioctl(struct inode *inode, struct file *file, | |
322 | unsigned int cmd, unsigned long arg) | |
323 | { | |
324 | int setopt = 0; | |
325 | struct wd_timer* pTimer = (struct wd_timer*)file->private_data; | |
326 | void __user *argp = (void __user *)arg; | |
327 | struct watchdog_info info = { | |
328 | 0, | |
329 | 0, | |
330 | "Altera EPF8820ATC144-4" | |
331 | }; | |
332 | ||
333 | if(NULL == pTimer) { | |
334 | return(-EINVAL); | |
335 | } | |
336 | ||
337 | switch(cmd) | |
338 | { | |
339 | /* Generic Linux IOCTLs */ | |
340 | case WDIOC_GETSUPPORT: | |
341 | if(copy_to_user(argp, &info, sizeof(struct watchdog_info))) { | |
342 | return(-EFAULT); | |
343 | } | |
344 | break; | |
345 | case WDIOC_GETSTATUS: | |
346 | case WDIOC_GETBOOTSTATUS: | |
347 | if (put_user(0, (int __user *)argp)) | |
348 | return -EFAULT; | |
349 | break; | |
350 | case WDIOC_KEEPALIVE: | |
351 | wd_pingtimer(pTimer); | |
352 | break; | |
353 | case WDIOC_SETOPTIONS: | |
354 | if(copy_from_user(&setopt, argp, sizeof(unsigned int))) { | |
355 | return -EFAULT; | |
356 | } | |
357 | if(setopt & WDIOS_DISABLECARD) { | |
358 | if(wd_dev.opt_enable) { | |
359 | printk( | |
360 | "%s: cannot disable watchdog in ENABLED mode\n", | |
361 | WD_OBPNAME); | |
362 | return(-EINVAL); | |
363 | } | |
364 | wd_stoptimer(pTimer); | |
365 | } | |
366 | else if(setopt & WDIOS_ENABLECARD) { | |
367 | wd_starttimer(pTimer); | |
368 | } | |
369 | else { | |
370 | return(-EINVAL); | |
371 | } | |
372 | break; | |
373 | /* Solaris-compatible IOCTLs */ | |
374 | case WIOCGSTAT: | |
375 | setopt = wd_getstatus(pTimer); | |
376 | if(copy_to_user(argp, &setopt, sizeof(unsigned int))) { | |
377 | return(-EFAULT); | |
378 | } | |
379 | break; | |
380 | case WIOCSTART: | |
381 | wd_starttimer(pTimer); | |
382 | break; | |
383 | case WIOCSTOP: | |
384 | if(wd_dev.opt_enable) { | |
385 | printk("%s: cannot disable watchdog in ENABLED mode\n", | |
386 | WD_OBPNAME); | |
387 | return(-EINVAL); | |
388 | } | |
389 | wd_stoptimer(pTimer); | |
390 | break; | |
391 | default: | |
392 | return(-EINVAL); | |
393 | } | |
394 | return(0); | |
395 | } | |
396 | ||
397 | static ssize_t wd_write(struct file *file, | |
398 | const char __user *buf, | |
399 | size_t count, | |
400 | loff_t *ppos) | |
401 | { | |
402 | struct wd_timer* pTimer = (struct wd_timer*)file->private_data; | |
403 | ||
404 | if(NULL == pTimer) { | |
405 | return(-EINVAL); | |
406 | } | |
407 | ||
408 | if (count) { | |
409 | wd_pingtimer(pTimer); | |
410 | return 1; | |
411 | } | |
412 | return 0; | |
413 | } | |
414 | ||
415 | static ssize_t wd_read(struct file * file, char __user *buffer, | |
416 | size_t count, loff_t *ppos) | |
417 | { | |
418 | #ifdef WD_DEBUG | |
419 | wd_dumpregs(); | |
420 | return(0); | |
421 | #else | |
422 | return(-EINVAL); | |
423 | #endif /* ifdef WD_DEBUG */ | |
424 | } | |
425 | ||
426 | static irqreturn_t wd_interrupt(int irq, void *dev_id, struct pt_regs *regs) | |
427 | { | |
428 | /* Only WD0 will interrupt-- others are NMI and we won't | |
429 | * see them here.... | |
430 | */ | |
431 | spin_lock_irq(&wd_dev.lock); | |
432 | if((unsigned long)wd_dev.regs == (unsigned long)dev_id) | |
433 | { | |
434 | wd_stoptimer(&wd_dev.watchdog[WD0_ID]); | |
435 | wd_dev.watchdog[WD0_ID].runstatus |= WD_STAT_SVCD; | |
436 | } | |
437 | spin_unlock_irq(&wd_dev.lock); | |
438 | return IRQ_HANDLED; | |
439 | } | |
440 | ||
441 | static struct file_operations wd_fops = { | |
442 | .owner = THIS_MODULE, | |
443 | .ioctl = wd_ioctl, | |
444 | .open = wd_open, | |
445 | .write = wd_write, | |
446 | .read = wd_read, | |
447 | .release = wd_release, | |
448 | }; | |
449 | ||
450 | static struct miscdevice wd0_miscdev = { WD0_MINOR, WD0_DEVNAME, &wd_fops }; | |
451 | static struct miscdevice wd1_miscdev = { WD1_MINOR, WD1_DEVNAME, &wd_fops }; | |
452 | static struct miscdevice wd2_miscdev = { WD2_MINOR, WD2_DEVNAME, &wd_fops }; | |
453 | ||
454 | #ifdef WD_DEBUG | |
455 | static void wd_dumpregs(void) | |
456 | { | |
457 | /* Reading from downcounters initiates watchdog countdown-- | |
458 | * Example is included below for illustration purposes. | |
459 | */ | |
460 | int i; | |
461 | printk("%s: dumping register values\n", WD_OBPNAME); | |
462 | for(i = WD0_ID; i < WD_NUMDEVS; ++i) { | |
463 | /* printk("\t%s%i: dcntr at 0x%lx: 0x%x\n", | |
464 | * WD_OBPNAME, | |
465 | * i, | |
466 | * (unsigned long)(&wd_dev.watchdog[i].regs->dcntr), | |
467 | * readw(&wd_dev.watchdog[i].regs->dcntr)); | |
468 | */ | |
469 | printk("\t%s%i: limit at 0x%lx: 0x%x\n", | |
470 | WD_OBPNAME, | |
471 | i, | |
472 | (unsigned long)(&wd_dev.watchdog[i].regs->limit), | |
473 | readw(&wd_dev.watchdog[i].regs->limit)); | |
474 | printk("\t%s%i: status at 0x%lx: 0x%x\n", | |
475 | WD_OBPNAME, | |
476 | i, | |
477 | (unsigned long)(&wd_dev.watchdog[i].regs->status), | |
478 | readb(&wd_dev.watchdog[i].regs->status)); | |
479 | printk("\t%s%i: driver status: 0x%x\n", | |
480 | WD_OBPNAME, | |
481 | i, | |
482 | wd_getstatus(&wd_dev.watchdog[i])); | |
483 | } | |
484 | printk("\tintr_mask at %p: 0x%x\n", | |
485 | wd_dev.regs + PLD_IMASK, | |
486 | readb(wd_dev.regs + PLD_IMASK)); | |
487 | printk("\tpld_status at %p: 0x%x\n", | |
488 | wd_dev.regs + PLD_STATUS, | |
489 | readb(wd_dev.regs + PLD_STATUS)); | |
490 | } | |
491 | #endif | |
492 | ||
493 | /* Enable or disable watchdog interrupts | |
494 | * Because of the CP1400 defect this should only be | |
495 | * called during initialzation or by wd_[start|stop]timer() | |
496 | * | |
497 | * pTimer - pointer to timer device, or NULL to indicate all timers | |
498 | * enable - non-zero to enable interrupts, zero to disable | |
499 | */ | |
500 | static void wd_toggleintr(struct wd_timer* pTimer, int enable) | |
501 | { | |
502 | unsigned char curregs = wd_readb(wd_dev.regs + PLD_IMASK); | |
503 | unsigned char setregs = | |
504 | (NULL == pTimer) ? | |
505 | (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : | |
506 | (pTimer->intr_mask); | |
507 | ||
508 | (WD_INTR_ON == enable) ? | |
509 | (curregs &= ~setregs): | |
510 | (curregs |= setregs); | |
511 | ||
512 | wd_writeb(curregs, wd_dev.regs + PLD_IMASK); | |
513 | return; | |
514 | } | |
515 | ||
516 | /* Reset countdown timer with 'limit' value and continue countdown. | |
517 | * This will not start a stopped timer. | |
518 | * | |
519 | * pTimer - pointer to timer device | |
520 | */ | |
521 | static void wd_pingtimer(struct wd_timer* pTimer) | |
522 | { | |
523 | if (wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) { | |
524 | wd_readw(pTimer->regs + WD_DCNTR); | |
525 | } | |
526 | } | |
527 | ||
528 | /* Stop a running watchdog timer-- the timer actually keeps | |
529 | * running, but the interrupt is masked so that no action is | |
530 | * taken upon expiration. | |
531 | * | |
532 | * pTimer - pointer to timer device | |
533 | */ | |
534 | static void wd_stoptimer(struct wd_timer* pTimer) | |
535 | { | |
536 | if(wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) { | |
537 | wd_toggleintr(pTimer, WD_INTR_OFF); | |
538 | ||
539 | if(wd_dev.isbaddoggie) { | |
540 | pTimer->runstatus |= WD_STAT_BSTOP; | |
541 | wd_brokentimer((unsigned long)&wd_dev); | |
542 | } | |
543 | } | |
544 | } | |
545 | ||
546 | /* Start a watchdog timer with the specified limit value | |
547 | * If the watchdog is running, it will be restarted with | |
548 | * the provided limit value. | |
549 | * | |
550 | * This function will enable interrupts on the specified | |
551 | * watchdog. | |
552 | * | |
553 | * pTimer - pointer to timer device | |
554 | * limit - limit (countdown) value in 1/10th seconds | |
555 | */ | |
556 | static void wd_starttimer(struct wd_timer* pTimer) | |
557 | { | |
558 | if(wd_dev.isbaddoggie) { | |
559 | pTimer->runstatus &= ~WD_STAT_BSTOP; | |
560 | } | |
561 | pTimer->runstatus &= ~WD_STAT_SVCD; | |
562 | ||
563 | wd_writew(pTimer->timeout, pTimer->regs + WD_LIMIT); | |
564 | wd_toggleintr(pTimer, WD_INTR_ON); | |
565 | } | |
566 | ||
567 | /* Restarts timer with maximum limit value and | |
568 | * does not unset 'brokenstop' value. | |
569 | */ | |
570 | static void wd_resetbrokentimer(struct wd_timer* pTimer) | |
571 | { | |
572 | wd_toggleintr(pTimer, WD_INTR_ON); | |
573 | wd_writew(WD_BLIMIT, pTimer->regs + WD_LIMIT); | |
574 | } | |
575 | ||
576 | /* Timer device initialization helper. | |
577 | * Returns 0 on success, other on failure | |
578 | */ | |
579 | static int wd_inittimer(int whichdog) | |
580 | { | |
581 | struct miscdevice *whichmisc; | |
582 | void __iomem *whichregs; | |
583 | char whichident[8]; | |
584 | int whichmask; | |
585 | __u16 whichlimit; | |
586 | ||
587 | switch(whichdog) | |
588 | { | |
589 | case WD0_ID: | |
590 | whichmisc = &wd0_miscdev; | |
591 | strcpy(whichident, "RIC"); | |
592 | whichregs = wd_dev.regs + WD0_OFF; | |
593 | whichmask = WD0_INTR_MASK; | |
594 | whichlimit= (0 == wd0_timeout) ? | |
595 | (wd_dev.opt_timeout): | |
596 | (wd0_timeout); | |
597 | break; | |
598 | case WD1_ID: | |
599 | whichmisc = &wd1_miscdev; | |
600 | strcpy(whichident, "XIR"); | |
601 | whichregs = wd_dev.regs + WD1_OFF; | |
602 | whichmask = WD1_INTR_MASK; | |
603 | whichlimit= (0 == wd1_timeout) ? | |
604 | (wd_dev.opt_timeout): | |
605 | (wd1_timeout); | |
606 | break; | |
607 | case WD2_ID: | |
608 | whichmisc = &wd2_miscdev; | |
609 | strcpy(whichident, "POR"); | |
610 | whichregs = wd_dev.regs + WD2_OFF; | |
611 | whichmask = WD2_INTR_MASK; | |
612 | whichlimit= (0 == wd2_timeout) ? | |
613 | (wd_dev.opt_timeout): | |
614 | (wd2_timeout); | |
615 | break; | |
616 | default: | |
617 | printk("%s: %s: invalid watchdog id: %i\n", | |
618 | WD_OBPNAME, __FUNCTION__, whichdog); | |
619 | return(1); | |
620 | } | |
621 | if(0 != misc_register(whichmisc)) | |
622 | { | |
623 | return(1); | |
624 | } | |
625 | wd_dev.watchdog[whichdog].regs = whichregs; | |
626 | wd_dev.watchdog[whichdog].timeout = whichlimit; | |
627 | wd_dev.watchdog[whichdog].intr_mask = whichmask; | |
628 | wd_dev.watchdog[whichdog].runstatus &= ~WD_STAT_BSTOP; | |
629 | wd_dev.watchdog[whichdog].runstatus |= WD_STAT_INIT; | |
630 | ||
631 | printk("%s%i: %s hardware watchdog [%01i.%i sec] %s\n", | |
632 | WD_OBPNAME, | |
633 | whichdog, | |
634 | whichident, | |
635 | wd_dev.watchdog[whichdog].timeout / 10, | |
636 | wd_dev.watchdog[whichdog].timeout % 10, | |
637 | (0 != wd_dev.opt_enable) ? "in ENABLED mode" : ""); | |
638 | return(0); | |
639 | } | |
640 | ||
641 | /* Timer method called to reset stopped watchdogs-- | |
642 | * because of the PLD bug on CP1400, we cannot mask | |
643 | * interrupts within the PLD so me must continually | |
644 | * reset the timers ad infinitum. | |
645 | */ | |
646 | static void wd_brokentimer(unsigned long data) | |
647 | { | |
648 | struct wd_device* pDev = (struct wd_device*)data; | |
649 | int id, tripped = 0; | |
650 | ||
651 | /* kill a running timer instance, in case we | |
652 | * were called directly instead of by kernel timer | |
653 | */ | |
654 | if(timer_pending(&wd_timer)) { | |
655 | del_timer(&wd_timer); | |
656 | } | |
657 | ||
658 | for(id = WD0_ID; id < WD_NUMDEVS; ++id) { | |
659 | if(pDev->watchdog[id].runstatus & WD_STAT_BSTOP) { | |
660 | ++tripped; | |
661 | wd_resetbrokentimer(&pDev->watchdog[id]); | |
662 | } | |
663 | } | |
664 | ||
665 | if(tripped) { | |
666 | /* there is at least one timer brokenstopped-- reschedule */ | |
667 | init_timer(&wd_timer); | |
668 | wd_timer.expires = WD_BTIMEOUT; | |
669 | add_timer(&wd_timer); | |
670 | } | |
671 | } | |
672 | ||
673 | static int wd_getstatus(struct wd_timer* pTimer) | |
674 | { | |
675 | unsigned char stat = wd_readb(pTimer->regs + WD_STATUS); | |
676 | unsigned char intr = wd_readb(wd_dev.regs + PLD_IMASK); | |
677 | unsigned char ret = WD_STOPPED; | |
678 | ||
679 | /* determine STOPPED */ | |
680 | if(0 == stat ) { | |
681 | return(ret); | |
682 | } | |
683 | /* determine EXPIRED vs FREERUN vs RUNNING */ | |
684 | else if(WD_S_EXPIRED & stat) { | |
685 | ret = WD_EXPIRED; | |
686 | } | |
687 | else if(WD_S_RUNNING & stat) { | |
688 | if(intr & pTimer->intr_mask) { | |
689 | ret = WD_FREERUN; | |
690 | } | |
691 | else { | |
692 | /* Fudge WD_EXPIRED status for defective CP1400-- | |
693 | * IF timer is running | |
694 | * AND brokenstop is set | |
695 | * AND an interrupt has been serviced | |
696 | * we are WD_EXPIRED. | |
697 | * | |
698 | * IF timer is running | |
699 | * AND brokenstop is set | |
700 | * AND no interrupt has been serviced | |
701 | * we are WD_FREERUN. | |
702 | */ | |
703 | if(wd_dev.isbaddoggie && (pTimer->runstatus & WD_STAT_BSTOP)) { | |
704 | if(pTimer->runstatus & WD_STAT_SVCD) { | |
705 | ret = WD_EXPIRED; | |
706 | } | |
707 | else { | |
708 | /* we could as well pretend we are expired */ | |
709 | ret = WD_FREERUN; | |
710 | } | |
711 | } | |
712 | else { | |
713 | ret = WD_RUNNING; | |
714 | } | |
715 | } | |
716 | } | |
717 | ||
718 | /* determine SERVICED */ | |
719 | if(pTimer->runstatus & WD_STAT_SVCD) { | |
720 | ret |= WD_SERVICED; | |
721 | } | |
722 | ||
723 | return(ret); | |
724 | } | |
725 | ||
726 | static int __init wd_init(void) | |
727 | { | |
728 | int id; | |
729 | struct linux_ebus *ebus = NULL; | |
730 | struct linux_ebus_device *edev = NULL; | |
731 | ||
732 | for_each_ebus(ebus) { | |
733 | for_each_ebusdev(edev, ebus) { | |
734 | if (!strcmp(edev->prom_name, WD_OBPNAME)) | |
735 | goto ebus_done; | |
736 | } | |
737 | } | |
738 | ||
739 | ebus_done: | |
740 | if(!edev) { | |
741 | printk("%s: unable to locate device\n", WD_OBPNAME); | |
742 | return -ENODEV; | |
743 | } | |
744 | ||
745 | wd_dev.regs = | |
746 | ioremap(edev->resource[0].start, 4 * WD_TIMER_REGSZ); /* ? */ | |
747 | ||
748 | if(NULL == wd_dev.regs) { | |
749 | printk("%s: unable to map registers\n", WD_OBPNAME); | |
750 | return(-ENODEV); | |
751 | } | |
752 | ||
753 | /* initialize device structure from OBP parameters */ | |
754 | wd_dev.irq = edev->irqs[0]; | |
755 | wd_dev.opt_enable = wd_opt_enable(); | |
756 | wd_dev.opt_reboot = wd_opt_reboot(); | |
757 | wd_dev.opt_timeout = wd_opt_timeout(); | |
758 | wd_dev.isbaddoggie = wd_isbroken(); | |
759 | ||
760 | /* disable all interrupts unless watchdog-enabled? == true */ | |
761 | if(! wd_dev.opt_enable) { | |
762 | wd_toggleintr(NULL, WD_INTR_OFF); | |
763 | } | |
764 | ||
765 | /* register miscellaneous devices */ | |
766 | for(id = WD0_ID; id < WD_NUMDEVS; ++id) { | |
767 | if(0 != wd_inittimer(id)) { | |
768 | printk("%s%i: unable to initialize\n", WD_OBPNAME, id); | |
769 | } | |
770 | } | |
771 | ||
772 | /* warn about possible defective PLD */ | |
773 | if(wd_dev.isbaddoggie) { | |
774 | init_timer(&wd_timer); | |
775 | wd_timer.function = wd_brokentimer; | |
776 | wd_timer.data = (unsigned long)&wd_dev; | |
777 | wd_timer.expires = WD_BTIMEOUT; | |
778 | ||
779 | printk("%s: PLD defect workaround enabled for model %s\n", | |
780 | WD_OBPNAME, WD_BADMODEL); | |
781 | } | |
782 | return(0); | |
783 | } | |
784 | ||
785 | static void __exit wd_cleanup(void) | |
786 | { | |
787 | int id; | |
788 | ||
789 | /* if 'watchdog-enable?' == TRUE, timers are not stopped | |
790 | * when module is unloaded. All brokenstopped timers will | |
791 | * also now eventually trip. | |
792 | */ | |
793 | for(id = WD0_ID; id < WD_NUMDEVS; ++id) { | |
794 | if(WD_S_RUNNING == wd_readb(wd_dev.watchdog[id].regs + WD_STATUS)) { | |
795 | if(wd_dev.opt_enable) { | |
796 | printk(KERN_WARNING "%s%i: timer not stopped at release\n", | |
797 | WD_OBPNAME, id); | |
798 | } | |
799 | else { | |
800 | wd_stoptimer(&wd_dev.watchdog[id]); | |
801 | if(wd_dev.watchdog[id].runstatus & WD_STAT_BSTOP) { | |
802 | wd_resetbrokentimer(&wd_dev.watchdog[id]); | |
803 | printk(KERN_WARNING | |
804 | "%s%i: defect workaround disabled at release, "\ | |
805 | "timer expires in ~%01i sec\n", | |
806 | WD_OBPNAME, id, | |
807 | wd_readw(wd_dev.watchdog[id].regs + WD_LIMIT) / 10); | |
808 | } | |
809 | } | |
810 | } | |
811 | } | |
812 | ||
813 | if(wd_dev.isbaddoggie && timer_pending(&wd_timer)) { | |
814 | del_timer(&wd_timer); | |
815 | } | |
816 | if(0 != (wd_dev.watchdog[WD0_ID].runstatus & WD_STAT_INIT)) { | |
817 | misc_deregister(&wd0_miscdev); | |
818 | } | |
819 | if(0 != (wd_dev.watchdog[WD1_ID].runstatus & WD_STAT_INIT)) { | |
820 | misc_deregister(&wd1_miscdev); | |
821 | } | |
822 | if(0 != (wd_dev.watchdog[WD2_ID].runstatus & WD_STAT_INIT)) { | |
823 | misc_deregister(&wd2_miscdev); | |
824 | } | |
825 | if(0 != wd_dev.initialized) { | |
826 | free_irq(wd_dev.irq, (void *)wd_dev.regs); | |
827 | } | |
828 | iounmap(wd_dev.regs); | |
829 | } | |
830 | ||
831 | module_init(wd_init); | |
832 | module_exit(wd_cleanup); |