sched: make early bootup sched_clock() use safer
[wrt350n-kernel.git] / drivers / watchdog / wdt_pci.c
blob1355608683e40e8c124c140981d66727a0fb4300
1 /*
2 * Industrial Computer Source PCI-WDT500/501 driver
4 * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
5 * http://www.redhat.com
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
12 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
16 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
18 * Release 0.10.
20 * Fixes
21 * Dave Gregorich : Modularisation and minor bugs
22 * Alan Cox : Added the watchdog ioctl() stuff
23 * Alan Cox : Fixed the reboot problem (as noted by
24 * Matt Crocker).
25 * Alan Cox : Added wdt= boot option
26 * Alan Cox : Cleaned up copy/user stuff
27 * Tim Hockin : Added insmod parameters, comment cleanup
28 * Parameterized timeout
29 * JP Nollmann : Added support for PCI wdt501p
30 * Alan Cox : Split ISA and PCI cards into two drivers
31 * Jeff Garzik : PCI cleanups
32 * Tigran Aivazian : Restructured wdtpci_init_one() to handle failures
33 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
34 * Zwane Mwaikambo : Magic char closing, locking changes, cleanups
35 * Matt Domsch : nowayout module option
38 #include <linux/interrupt.h>
39 #include <linux/module.h>
40 #include <linux/moduleparam.h>
41 #include <linux/types.h>
42 #include <linux/miscdevice.h>
43 #include <linux/watchdog.h>
44 #include <linux/ioport.h>
45 #include <linux/notifier.h>
46 #include <linux/reboot.h>
47 #include <linux/init.h>
48 #include <linux/fs.h>
49 #include <linux/pci.h>
51 #include <asm/io.h>
52 #include <asm/uaccess.h>
53 #include <asm/system.h>
55 #define WDT_IS_PCI
56 #include "wd501p.h"
58 #define PFX "wdt_pci: "
61 * Until Access I/O gets their application for a PCI vendor ID approved,
62 * I don't think that it's appropriate to move these constants into the
63 * regular pci_ids.h file. -- JPN 2000/01/18
66 #ifndef PCI_VENDOR_ID_ACCESSIO
67 #define PCI_VENDOR_ID_ACCESSIO 0x494f
68 #endif
69 #ifndef PCI_DEVICE_ID_WDG_CSM
70 #define PCI_DEVICE_ID_WDG_CSM 0x22c0
71 #endif
73 /* We can only use 1 card due to the /dev/watchdog restriction */
74 static int dev_count;
76 static struct semaphore open_sem;
77 static DEFINE_SPINLOCK(wdtpci_lock);
78 static char expect_close;
80 static int io;
81 static int irq;
83 /* Default timeout */
84 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */
86 static int heartbeat = WD_TIMO;
87 static int wd_heartbeat;
88 module_param(heartbeat, int, 0);
89 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WD_TIMO) ")");
91 static int nowayout = WATCHDOG_NOWAYOUT;
92 module_param(nowayout, int, 0);
93 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
95 #ifdef CONFIG_WDT_501_PCI
96 /* Support for the Fan Tachometer on the PCI-WDT501 */
97 static int tachometer;
99 module_param(tachometer, int, 0);
100 MODULE_PARM_DESC(tachometer, "PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
101 #endif /* CONFIG_WDT_501_PCI */
104 * Programming support
107 static void wdtpci_ctr_mode(int ctr, int mode)
109 ctr<<=6;
110 ctr|=0x30;
111 ctr|=(mode<<1);
112 outb_p(ctr, WDT_CR);
115 static void wdtpci_ctr_load(int ctr, int val)
117 outb_p(val&0xFF, WDT_COUNT0+ctr);
118 outb_p(val>>8, WDT_COUNT0+ctr);
122 * wdtpci_start:
124 * Start the watchdog driver.
127 static int wdtpci_start(void)
129 unsigned long flags;
131 spin_lock_irqsave(&wdtpci_lock, flags);
134 * "pet" the watchdog, as Access says.
135 * This resets the clock outputs.
137 inb_p(WDT_DC); /* Disable watchdog */
138 wdtpci_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */
139 outb_p(0, WDT_DC); /* Enable watchdog */
141 inb_p(WDT_DC); /* Disable watchdog */
142 outb_p(0, WDT_CLOCK); /* 2.0833MHz clock */
143 inb_p(WDT_BUZZER); /* disable */
144 inb_p(WDT_OPTONOTRST); /* disable */
145 inb_p(WDT_OPTORST); /* disable */
146 inb_p(WDT_PROGOUT); /* disable */
147 wdtpci_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */
148 wdtpci_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */
149 wdtpci_ctr_mode(2,1); /* Program CTR2 for Mode 1: Retriggerable One-Shot */
150 wdtpci_ctr_load(0,20833); /* count at 100Hz */
151 wdtpci_ctr_load(1,wd_heartbeat);/* Heartbeat */
152 /* DO NOT LOAD CTR2 on PCI card! -- JPN */
153 outb_p(0, WDT_DC); /* Enable watchdog */
155 spin_unlock_irqrestore(&wdtpci_lock, flags);
156 return 0;
160 * wdtpci_stop:
162 * Stop the watchdog driver.
165 static int wdtpci_stop (void)
167 unsigned long flags;
169 /* Turn the card off */
170 spin_lock_irqsave(&wdtpci_lock, flags);
171 inb_p(WDT_DC); /* Disable watchdog */
172 wdtpci_ctr_load(2,0); /* 0 length reset pulses now */
173 spin_unlock_irqrestore(&wdtpci_lock, flags);
174 return 0;
178 * wdtpci_ping:
180 * Reload counter one with the watchdog heartbeat. We don't bother reloading
181 * the cascade counter.
184 static int wdtpci_ping(void)
186 unsigned long flags;
188 /* Write a watchdog value */
189 spin_lock_irqsave(&wdtpci_lock, flags);
190 inb_p(WDT_DC); /* Disable watchdog */
191 wdtpci_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */
192 wdtpci_ctr_load(1,wd_heartbeat);/* Heartbeat */
193 outb_p(0, WDT_DC); /* Enable watchdog */
194 spin_unlock_irqrestore(&wdtpci_lock, flags);
195 return 0;
199 * wdtpci_set_heartbeat:
200 * @t: the new heartbeat value that needs to be set.
202 * Set a new heartbeat value for the watchdog device. If the heartbeat value is
203 * incorrect we keep the old value and return -EINVAL. If successfull we
204 * return 0.
206 static int wdtpci_set_heartbeat(int t)
208 /* Arbitrary, can't find the card's limits */
209 if ((t < 1) || (t > 65535))
210 return -EINVAL;
212 heartbeat = t;
213 wd_heartbeat = t * 100;
214 return 0;
218 * wdtpci_get_status:
219 * @status: the new status.
221 * Extract the status information from a WDT watchdog device. There are
222 * several board variants so we have to know which bits are valid. Some
223 * bits default to one and some to zero in order to be maximally painful.
225 * we then map the bits onto the status ioctl flags.
228 static int wdtpci_get_status(int *status)
230 unsigned char new_status=inb_p(WDT_SR);
232 *status=0;
233 if (new_status & WDC_SR_ISOI0)
234 *status |= WDIOF_EXTERN1;
235 if (new_status & WDC_SR_ISII1)
236 *status |= WDIOF_EXTERN2;
237 #ifdef CONFIG_WDT_501_PCI
238 if (!(new_status & WDC_SR_TGOOD))
239 *status |= WDIOF_OVERHEAT;
240 if (!(new_status & WDC_SR_PSUOVER))
241 *status |= WDIOF_POWEROVER;
242 if (!(new_status & WDC_SR_PSUUNDR))
243 *status |= WDIOF_POWERUNDER;
244 if (tachometer) {
245 if (!(new_status & WDC_SR_FANGOOD))
246 *status |= WDIOF_FANFAULT;
248 #endif /* CONFIG_WDT_501_PCI */
249 return 0;
252 #ifdef CONFIG_WDT_501_PCI
254 * wdtpci_get_temperature:
256 * Reports the temperature in degrees Fahrenheit. The API is in
257 * farenheit. It was designed by an imperial measurement luddite.
260 static int wdtpci_get_temperature(int *temperature)
262 unsigned short c=inb_p(WDT_RT);
264 *temperature = (c * 11 / 15) + 7;
265 return 0;
267 #endif /* CONFIG_WDT_501_PCI */
270 * wdtpci_interrupt:
271 * @irq: Interrupt number
272 * @dev_id: Unused as we don't allow multiple devices.
274 * Handle an interrupt from the board. These are raised when the status
275 * map changes in what the board considers an interesting way. That means
276 * a failure condition occurring.
279 static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
282 * Read the status register see what is up and
283 * then printk it.
285 unsigned char status=inb_p(WDT_SR);
287 printk(KERN_CRIT PFX "status %d\n", status);
289 #ifdef CONFIG_WDT_501_PCI
290 if (!(status & WDC_SR_TGOOD))
291 printk(KERN_CRIT PFX "Overheat alarm.(%d)\n",inb_p(WDT_RT));
292 if (!(status & WDC_SR_PSUOVER))
293 printk(KERN_CRIT PFX "PSU over voltage.\n");
294 if (!(status & WDC_SR_PSUUNDR))
295 printk(KERN_CRIT PFX "PSU under voltage.\n");
296 if (tachometer) {
297 if (!(status & WDC_SR_FANGOOD))
298 printk(KERN_CRIT PFX "Possible fan fault.\n");
300 #endif /* CONFIG_WDT_501_PCI */
301 if (!(status&WDC_SR_WCCR)) {
302 #ifdef SOFTWARE_REBOOT
303 #ifdef ONLY_TESTING
304 printk(KERN_CRIT PFX "Would Reboot.\n");
305 #else
306 printk(KERN_CRIT PFX "Initiating system reboot.\n");
307 emergency_restart(NULL);
308 #endif
309 #else
310 printk(KERN_CRIT PFX "Reset in 5ms.\n");
311 #endif
313 return IRQ_HANDLED;
318 * wdtpci_write:
319 * @file: file handle to the watchdog
320 * @buf: buffer to write (unused as data does not matter here
321 * @count: count of bytes
322 * @ppos: pointer to the position to write. No seeks allowed
324 * A write to a watchdog device is defined as a keepalive signal. Any
325 * write of data will do, as we we don't define content meaning.
328 static ssize_t wdtpci_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
330 if (count) {
331 if (!nowayout) {
332 size_t i;
334 expect_close = 0;
336 for (i = 0; i != count; i++) {
337 char c;
338 if(get_user(c, buf+i))
339 return -EFAULT;
340 if (c == 'V')
341 expect_close = 42;
344 wdtpci_ping();
347 return count;
351 * wdtpci_ioctl:
352 * @inode: inode of the device
353 * @file: file handle to the device
354 * @cmd: watchdog command
355 * @arg: argument pointer
357 * The watchdog API defines a common set of functions for all watchdogs
358 * according to their available features. We only actually usefully support
359 * querying capabilities and current status.
362 static int wdtpci_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
363 unsigned long arg)
365 int new_heartbeat;
366 int status;
367 void __user *argp = (void __user *)arg;
368 int __user *p = argp;
370 static struct watchdog_info ident = {
371 .options = WDIOF_SETTIMEOUT|
372 WDIOF_MAGICCLOSE|
373 WDIOF_KEEPALIVEPING,
374 .firmware_version = 1,
375 .identity = "PCI-WDT500/501",
378 /* Add options according to the card we have */
379 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
380 #ifdef CONFIG_WDT_501_PCI
381 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER);
382 if (tachometer)
383 ident.options |= WDIOF_FANFAULT;
384 #endif /* CONFIG_WDT_501_PCI */
386 switch(cmd)
388 default:
389 return -ENOTTY;
390 case WDIOC_GETSUPPORT:
391 return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
393 case WDIOC_GETSTATUS:
394 wdtpci_get_status(&status);
395 return put_user(status, p);
396 case WDIOC_GETBOOTSTATUS:
397 return put_user(0, p);
398 case WDIOC_KEEPALIVE:
399 wdtpci_ping();
400 return 0;
401 case WDIOC_SETTIMEOUT:
402 if (get_user(new_heartbeat, p))
403 return -EFAULT;
405 if (wdtpci_set_heartbeat(new_heartbeat))
406 return -EINVAL;
408 wdtpci_ping();
409 /* Fall */
410 case WDIOC_GETTIMEOUT:
411 return put_user(heartbeat, p);
416 * wdtpci_open:
417 * @inode: inode of device
418 * @file: file handle to device
420 * The watchdog device has been opened. The watchdog device is single
421 * open and on opening we load the counters. Counter zero is a 100Hz
422 * cascade, into counter 1 which downcounts to reboot. When the counter
423 * triggers counter 2 downcounts the length of the reset pulse which
424 * set set to be as long as possible.
427 static int wdtpci_open(struct inode *inode, struct file *file)
429 if (down_trylock(&open_sem))
430 return -EBUSY;
432 if (nowayout) {
433 __module_get(THIS_MODULE);
436 * Activate
438 wdtpci_start();
439 return nonseekable_open(inode, file);
443 * wdtpci_release:
444 * @inode: inode to board
445 * @file: file handle to board
447 * The watchdog has a configurable API. There is a religious dispute
448 * between people who want their watchdog to be able to shut down and
449 * those who want to be sure if the watchdog manager dies the machine
450 * reboots. In the former case we disable the counters, in the latter
451 * case you have to open it again very soon.
454 static int wdtpci_release(struct inode *inode, struct file *file)
456 if (expect_close == 42) {
457 wdtpci_stop();
458 } else {
459 printk(KERN_CRIT PFX "Unexpected close, not stopping timer!");
460 wdtpci_ping();
462 expect_close = 0;
463 up(&open_sem);
464 return 0;
467 #ifdef CONFIG_WDT_501_PCI
469 * wdtpci_temp_read:
470 * @file: file handle to the watchdog board
471 * @buf: buffer to write 1 byte into
472 * @count: length of buffer
473 * @ptr: offset (no seek allowed)
475 * Read reports the temperature in degrees Fahrenheit. The API is in
476 * fahrenheit. It was designed by an imperial measurement luddite.
479 static ssize_t wdtpci_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
481 int temperature;
483 if (wdtpci_get_temperature(&temperature))
484 return -EFAULT;
486 if (copy_to_user (buf, &temperature, 1))
487 return -EFAULT;
489 return 1;
493 * wdtpci_temp_open:
494 * @inode: inode of device
495 * @file: file handle to device
497 * The temperature device has been opened.
500 static int wdtpci_temp_open(struct inode *inode, struct file *file)
502 return nonseekable_open(inode, file);
506 * wdtpci_temp_release:
507 * @inode: inode to board
508 * @file: file handle to board
510 * The temperature device has been closed.
513 static int wdtpci_temp_release(struct inode *inode, struct file *file)
515 return 0;
517 #endif /* CONFIG_WDT_501_PCI */
520 * notify_sys:
521 * @this: our notifier block
522 * @code: the event being reported
523 * @unused: unused
525 * Our notifier is called on system shutdowns. We want to turn the card
526 * off at reboot otherwise the machine will reboot again during memory
527 * test or worse yet during the following fsck. This would suck, in fact
528 * trust me - if it happens it does suck.
531 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
532 void *unused)
534 if (code==SYS_DOWN || code==SYS_HALT) {
535 /* Turn the card off */
536 wdtpci_stop();
538 return NOTIFY_DONE;
542 * Kernel Interfaces
546 static const struct file_operations wdtpci_fops = {
547 .owner = THIS_MODULE,
548 .llseek = no_llseek,
549 .write = wdtpci_write,
550 .ioctl = wdtpci_ioctl,
551 .open = wdtpci_open,
552 .release = wdtpci_release,
555 static struct miscdevice wdtpci_miscdev = {
556 .minor = WATCHDOG_MINOR,
557 .name = "watchdog",
558 .fops = &wdtpci_fops,
561 #ifdef CONFIG_WDT_501_PCI
562 static const struct file_operations wdtpci_temp_fops = {
563 .owner = THIS_MODULE,
564 .llseek = no_llseek,
565 .read = wdtpci_temp_read,
566 .open = wdtpci_temp_open,
567 .release = wdtpci_temp_release,
570 static struct miscdevice temp_miscdev = {
571 .minor = TEMP_MINOR,
572 .name = "temperature",
573 .fops = &wdtpci_temp_fops,
575 #endif /* CONFIG_WDT_501_PCI */
578 * The WDT card needs to learn about soft shutdowns in order to
579 * turn the timebomb registers off.
582 static struct notifier_block wdtpci_notifier = {
583 .notifier_call = wdtpci_notify_sys,
587 static int __devinit wdtpci_init_one (struct pci_dev *dev,
588 const struct pci_device_id *ent)
590 int ret = -EIO;
592 dev_count++;
593 if (dev_count > 1) {
594 printk (KERN_ERR PFX "this driver only supports 1 device\n");
595 return -ENODEV;
598 if (pci_enable_device (dev)) {
599 printk (KERN_ERR PFX "Not possible to enable PCI Device\n");
600 return -ENODEV;
603 if (pci_resource_start (dev, 2) == 0x0000) {
604 printk (KERN_ERR PFX "No I/O-Address for card detected\n");
605 ret = -ENODEV;
606 goto out_pci;
609 sema_init(&open_sem, 1);
611 irq = dev->irq;
612 io = pci_resource_start (dev, 2);
614 if (request_region (io, 16, "wdt_pci") == NULL) {
615 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", io);
616 goto out_pci;
619 if (request_irq (irq, wdtpci_interrupt, IRQF_DISABLED | IRQF_SHARED,
620 "wdt_pci", &wdtpci_miscdev)) {
621 printk (KERN_ERR PFX "IRQ %d is not free\n", irq);
622 goto out_reg;
625 printk ("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%04x (Interrupt %d)\n",
626 io, irq);
628 /* Check that the heartbeat value is within it's range ; if not reset to the default */
629 if (wdtpci_set_heartbeat(heartbeat)) {
630 wdtpci_set_heartbeat(WD_TIMO);
631 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
632 WD_TIMO);
635 ret = register_reboot_notifier (&wdtpci_notifier);
636 if (ret) {
637 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
638 goto out_irq;
641 #ifdef CONFIG_WDT_501_PCI
642 ret = misc_register (&temp_miscdev);
643 if (ret) {
644 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
645 TEMP_MINOR, ret);
646 goto out_rbt;
648 #endif /* CONFIG_WDT_501_PCI */
650 ret = misc_register (&wdtpci_miscdev);
651 if (ret) {
652 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
653 WATCHDOG_MINOR, ret);
654 goto out_misc;
657 printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
658 heartbeat, nowayout);
659 #ifdef CONFIG_WDT_501_PCI
660 printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled"));
661 #endif /* CONFIG_WDT_501_PCI */
663 ret = 0;
664 out:
665 return ret;
667 out_misc:
668 #ifdef CONFIG_WDT_501_PCI
669 misc_deregister(&temp_miscdev);
670 out_rbt:
671 #endif /* CONFIG_WDT_501_PCI */
672 unregister_reboot_notifier(&wdtpci_notifier);
673 out_irq:
674 free_irq(irq, &wdtpci_miscdev);
675 out_reg:
676 release_region (io, 16);
677 out_pci:
678 pci_disable_device(dev);
679 goto out;
683 static void __devexit wdtpci_remove_one (struct pci_dev *pdev)
685 /* here we assume only one device will ever have
686 * been picked up and registered by probe function */
687 misc_deregister(&wdtpci_miscdev);
688 #ifdef CONFIG_WDT_501_PCI
689 misc_deregister(&temp_miscdev);
690 #endif /* CONFIG_WDT_501_PCI */
691 unregister_reboot_notifier(&wdtpci_notifier);
692 free_irq(irq, &wdtpci_miscdev);
693 release_region(io, 16);
694 pci_disable_device(pdev);
695 dev_count--;
699 static struct pci_device_id wdtpci_pci_tbl[] = {
701 .vendor = PCI_VENDOR_ID_ACCESSIO,
702 .device = PCI_DEVICE_ID_WDG_CSM,
703 .subvendor = PCI_ANY_ID,
704 .subdevice = PCI_ANY_ID,
706 { 0, }, /* terminate list */
708 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
711 static struct pci_driver wdtpci_driver = {
712 .name = "wdt_pci",
713 .id_table = wdtpci_pci_tbl,
714 .probe = wdtpci_init_one,
715 .remove = __devexit_p(wdtpci_remove_one),
720 * wdtpci_cleanup:
722 * Unload the watchdog. You cannot do this with any file handles open.
723 * If your watchdog is set to continue ticking on close and you unload
724 * it, well it keeps ticking. We won't get the interrupt but the board
725 * will not touch PC memory so all is fine. You just have to load a new
726 * module in xx seconds or reboot.
729 static void __exit wdtpci_cleanup(void)
731 pci_unregister_driver (&wdtpci_driver);
736 * wdtpci_init:
738 * Set up the WDT watchdog board. All we have to do is grab the
739 * resources we require and bitch if anyone beat us to them.
740 * The open() function will actually kick the board off.
743 static int __init wdtpci_init(void)
745 return pci_register_driver (&wdtpci_driver);
749 module_init(wdtpci_init);
750 module_exit(wdtpci_cleanup);
752 MODULE_AUTHOR("JP Nollmann, Alan Cox");
753 MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
754 MODULE_LICENSE("GPL");
755 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
756 MODULE_ALIAS_MISCDEV(TEMP_MINOR);