1/*
2 *	Industrial Computer Source PCI-WDT500/501 driver
3 *
4 *	(c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
5 *						All Rights Reserved.
6 *
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.
11 *
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.
15 *
16 *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
17 *
18 *	Release 0.10.
19 *
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
33 *					failures
34 *		Joel Becker	:	Added WDIOC_GET/SETTIMEOUT
35 *		Zwane Mwaikambo	:	Magic char closing, locking changes,
36 *					cleanups
37 *		Matt Domsch	:	nowayout module option
38 */
39
40#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
41
42#include <linux/interrupt.h>
43#include <linux/module.h>
44#include <linux/moduleparam.h>
45#include <linux/types.h>
46#include <linux/miscdevice.h>
47#include <linux/watchdog.h>
48#include <linux/ioport.h>
49#include <linux/delay.h>
50#include <linux/notifier.h>
51#include <linux/reboot.h>
52#include <linux/fs.h>
53#include <linux/pci.h>
54#include <linux/io.h>
55#include <linux/uaccess.h>
56
57
58#define WDT_IS_PCI
59#include "wd501p.h"
60
61/* We can only use 1 card due to the /dev/watchdog restriction */
62static int dev_count;
63
64static unsigned long open_lock;
65static DEFINE_SPINLOCK(wdtpci_lock);
66static char expect_close;
67
68static resource_size_t io;
69static int irq;
70
71/* Default timeout */
72#define WD_TIMO 60			/* Default heartbeat = 60 seconds */
73
74static int heartbeat = WD_TIMO;
75static int wd_heartbeat;
76module_param(heartbeat, int, 0);
77MODULE_PARM_DESC(heartbeat,
78		"Watchdog heartbeat in seconds. (0<heartbeat<65536, default="
79				__MODULE_STRING(WD_TIMO) ")");
80
81static bool nowayout = WATCHDOG_NOWAYOUT;
82module_param(nowayout, bool, 0);
83MODULE_PARM_DESC(nowayout,
84		"Watchdog cannot be stopped once started (default="
85				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
86
87/* Support for the Fan Tachometer on the PCI-WDT501 */
88static int tachometer;
89module_param(tachometer, int, 0);
90MODULE_PARM_DESC(tachometer,
91		"PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
92
93static int type = 500;
94module_param(type, int, 0);
95MODULE_PARM_DESC(type,
96		"PCI-WDT501 Card type (500 or 501 , default=500)");
97
98/*
99 *	Programming support
100 */
101
102static void wdtpci_ctr_mode(int ctr, int mode)
103{
104	ctr <<= 6;
105	ctr |= 0x30;
106	ctr |= (mode << 1);
107	outb(ctr, WDT_CR);
108	udelay(8);
109}
110
111static void wdtpci_ctr_load(int ctr, int val)
112{
113	outb(val & 0xFF, WDT_COUNT0 + ctr);
114	udelay(8);
115	outb(val >> 8, WDT_COUNT0 + ctr);
116	udelay(8);
117}
118
119/**
120 *	wdtpci_start:
121 *
122 *	Start the watchdog driver.
123 */
124
125static int wdtpci_start(void)
126{
127	unsigned long flags;
128
129	spin_lock_irqsave(&wdtpci_lock, flags);
130
131	/*
132	 * "pet" the watchdog, as Access says.
133	 * This resets the clock outputs.
134	 */
135	inb(WDT_DC);			/* Disable watchdog */
136	udelay(8);
137	wdtpci_ctr_mode(2, 0);		/* Program CTR2 for Mode 0:
138						Pulse on Terminal Count */
139	outb(0, WDT_DC);		/* Enable watchdog */
140	udelay(8);
141	inb(WDT_DC);			/* Disable watchdog */
142	udelay(8);
143	outb(0, WDT_CLOCK);		/* 2.0833MHz clock */
144	udelay(8);
145	inb(WDT_BUZZER);		/* disable */
146	udelay(8);
147	inb(WDT_OPTONOTRST);		/* disable */
148	udelay(8);
149	inb(WDT_OPTORST);		/* disable */
150	udelay(8);
151	inb(WDT_PROGOUT);		/* disable */
152	udelay(8);
153	wdtpci_ctr_mode(0, 3);		/* Program CTR0 for Mode 3:
154						Square Wave Generator */
155	wdtpci_ctr_mode(1, 2);		/* Program CTR1 for Mode 2:
156						Rate Generator */
157	wdtpci_ctr_mode(2, 1);		/* Program CTR2 for Mode 1:
158						Retriggerable One-Shot */
159	wdtpci_ctr_load(0, 20833);	/* count at 100Hz */
160	wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
161	/* DO NOT LOAD CTR2 on PCI card! -- JPN */
162	outb(0, WDT_DC);		/* Enable watchdog */
163	udelay(8);
164
165	spin_unlock_irqrestore(&wdtpci_lock, flags);
166	return 0;
167}
168
169/**
170 *	wdtpci_stop:
171 *
172 *	Stop the watchdog driver.
173 */
174
175static int wdtpci_stop(void)
176{
177	unsigned long flags;
178
179	/* Turn the card off */
180	spin_lock_irqsave(&wdtpci_lock, flags);
181	inb(WDT_DC);			/* Disable watchdog */
182	udelay(8);
183	wdtpci_ctr_load(2, 0);		/* 0 length reset pulses now */
184	spin_unlock_irqrestore(&wdtpci_lock, flags);
185	return 0;
186}
187
188/**
189 *	wdtpci_ping:
190 *
191 *	Reload counter one with the watchdog heartbeat. We don't bother
192 *	reloading the cascade counter.
193 */
194
195static int wdtpci_ping(void)
196{
197	unsigned long flags;
198
199	spin_lock_irqsave(&wdtpci_lock, flags);
200	/* Write a watchdog value */
201	inb(WDT_DC);			/* Disable watchdog */
202	udelay(8);
203	wdtpci_ctr_mode(1, 2);		/* Re-Program CTR1 for Mode 2:
204							Rate Generator */
205	wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
206	outb(0, WDT_DC);		/* Enable watchdog */
207	udelay(8);
208	spin_unlock_irqrestore(&wdtpci_lock, flags);
209	return 0;
210}
211
212/**
213 *	wdtpci_set_heartbeat:
214 *	@t:		the new heartbeat value that needs to be set.
215 *
216 *	Set a new heartbeat value for the watchdog device. If the heartbeat
217 *	value is incorrect we keep the old value and return -EINVAL.
218 *	If successful we return 0.
219 */
220static int wdtpci_set_heartbeat(int t)
221{
222	/* Arbitrary, can't find the card's limits */
223	if (t < 1 || t > 65535)
224		return -EINVAL;
225
226	heartbeat = t;
227	wd_heartbeat = t * 100;
228	return 0;
229}
230
231/**
232 *	wdtpci_get_status:
233 *	@status:		the new status.
234 *
235 *	Extract the status information from a WDT watchdog device. There are
236 *	several board variants so we have to know which bits are valid. Some
237 *	bits default to one and some to zero in order to be maximally painful.
238 *
239 *	we then map the bits onto the status ioctl flags.
240 */
241
242static int wdtpci_get_status(int *status)
243{
244	unsigned char new_status;
245	unsigned long flags;
246
247	spin_lock_irqsave(&wdtpci_lock, flags);
248	new_status = inb(WDT_SR);
249	spin_unlock_irqrestore(&wdtpci_lock, flags);
250
251	*status = 0;
252	if (new_status & WDC_SR_ISOI0)
253		*status |= WDIOF_EXTERN1;
254	if (new_status & WDC_SR_ISII1)
255		*status |= WDIOF_EXTERN2;
256	if (type == 501) {
257		if (!(new_status & WDC_SR_TGOOD))
258			*status |= WDIOF_OVERHEAT;
259		if (!(new_status & WDC_SR_PSUOVER))
260			*status |= WDIOF_POWEROVER;
261		if (!(new_status & WDC_SR_PSUUNDR))
262			*status |= WDIOF_POWERUNDER;
263		if (tachometer) {
264			if (!(new_status & WDC_SR_FANGOOD))
265				*status |= WDIOF_FANFAULT;
266		}
267	}
268	return 0;
269}
270
271/**
272 *	wdtpci_get_temperature:
273 *
274 *	Reports the temperature in degrees Fahrenheit. The API is in
275 *	farenheit. It was designed by an imperial measurement luddite.
276 */
277
278static int wdtpci_get_temperature(int *temperature)
279{
280	unsigned short c;
281	unsigned long flags;
282	spin_lock_irqsave(&wdtpci_lock, flags);
283	c = inb(WDT_RT);
284	udelay(8);
285	spin_unlock_irqrestore(&wdtpci_lock, flags);
286	*temperature = (c * 11 / 15) + 7;
287	return 0;
288}
289
290/**
291 *	wdtpci_interrupt:
292 *	@irq:		Interrupt number
293 *	@dev_id:	Unused as we don't allow multiple devices.
294 *
295 *	Handle an interrupt from the board. These are raised when the status
296 *	map changes in what the board considers an interesting way. That means
297 *	a failure condition occurring.
298 */
299
300static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
301{
302	/*
303	 *	Read the status register see what is up and
304	 *	then printk it.
305	 */
306	unsigned char status;
307
308	spin_lock(&wdtpci_lock);
309
310	status = inb(WDT_SR);
311	udelay(8);
312
313	pr_crit("status %d\n", status);
314
315	if (type == 501) {
316		if (!(status & WDC_SR_TGOOD)) {
317			pr_crit("Overheat alarm (%d)\n", inb(WDT_RT));
318			udelay(8);
319		}
320		if (!(status & WDC_SR_PSUOVER))
321			pr_crit("PSU over voltage\n");
322		if (!(status & WDC_SR_PSUUNDR))
323			pr_crit("PSU under voltage\n");
324		if (tachometer) {
325			if (!(status & WDC_SR_FANGOOD))
326				pr_crit("Possible fan fault\n");
327		}
328	}
329	if (!(status & WDC_SR_WCCR)) {
330#ifdef SOFTWARE_REBOOT
331#ifdef ONLY_TESTING
332		pr_crit("Would Reboot\n");
333#else
334		pr_crit("Initiating system reboot\n");
335		emergency_restart(NULL);
336#endif
337#else
338		pr_crit("Reset in 5ms\n");
339#endif
340	}
341	spin_unlock(&wdtpci_lock);
342	return IRQ_HANDLED;
343}
344
345
346/**
347 *	wdtpci_write:
348 *	@file: file handle to the watchdog
349 *	@buf: buffer to write (unused as data does not matter here
350 *	@count: count of bytes
351 *	@ppos: pointer to the position to write. No seeks allowed
352 *
353 *	A write to a watchdog device is defined as a keepalive signal. Any
354 *	write of data will do, as we we don't define content meaning.
355 */
356
357static ssize_t wdtpci_write(struct file *file, const char __user *buf,
358						size_t count, loff_t *ppos)
359{
360	if (count) {
361		if (!nowayout) {
362			size_t i;
363
364			/* In case it was set long ago */
365			expect_close = 0;
366
367			for (i = 0; i != count; i++) {
368				char c;
369				if (get_user(c, buf + i))
370					return -EFAULT;
371				if (c == 'V')
372					expect_close = 42;
373			}
374		}
375		wdtpci_ping();
376	}
377	return count;
378}
379
380/**
381 *	wdtpci_ioctl:
382 *	@file: file handle to the device
383 *	@cmd: watchdog command
384 *	@arg: argument pointer
385 *
386 *	The watchdog API defines a common set of functions for all watchdogs
387 *	according to their available features. We only actually usefully support
388 *	querying capabilities and current status.
389 */
390
391static long wdtpci_ioctl(struct file *file, unsigned int cmd,
392							unsigned long arg)
393{
394	void __user *argp = (void __user *)arg;
395	int __user *p = argp;
396	int new_heartbeat;
397	int status;
398
399	struct watchdog_info ident = {
400		.options =		WDIOF_SETTIMEOUT|
401					WDIOF_MAGICCLOSE|
402					WDIOF_KEEPALIVEPING,
403		.firmware_version =	1,
404		.identity =		"PCI-WDT500/501",
405	};
406
407	/* Add options according to the card we have */
408	ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
409	if (type == 501) {
410		ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
411							WDIOF_POWEROVER);
412		if (tachometer)
413			ident.options |= WDIOF_FANFAULT;
414	}
415
416	switch (cmd) {
417	case WDIOC_GETSUPPORT:
418		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
419	case WDIOC_GETSTATUS:
420		wdtpci_get_status(&status);
421		return put_user(status, p);
422	case WDIOC_GETBOOTSTATUS:
423		return put_user(0, p);
424	case WDIOC_KEEPALIVE:
425		wdtpci_ping();
426		return 0;
427	case WDIOC_SETTIMEOUT:
428		if (get_user(new_heartbeat, p))
429			return -EFAULT;
430		if (wdtpci_set_heartbeat(new_heartbeat))
431			return -EINVAL;
432		wdtpci_ping();
433		/* Fall */
434	case WDIOC_GETTIMEOUT:
435		return put_user(heartbeat, p);
436	default:
437		return -ENOTTY;
438	}
439}
440
441/**
442 *	wdtpci_open:
443 *	@inode: inode of device
444 *	@file: file handle to device
445 *
446 *	The watchdog device has been opened. The watchdog device is single
447 *	open and on opening we load the counters. Counter zero is a 100Hz
448 *	cascade, into counter 1 which downcounts to reboot. When the counter
449 *	triggers counter 2 downcounts the length of the reset pulse which
450 *	set set to be as long as possible.
451 */
452
453static int wdtpci_open(struct inode *inode, struct file *file)
454{
455	if (test_and_set_bit(0, &open_lock))
456		return -EBUSY;
457
458	if (nowayout)
459		__module_get(THIS_MODULE);
460	/*
461	 *	Activate
462	 */
463	wdtpci_start();
464	return nonseekable_open(inode, file);
465}
466
467/**
468 *	wdtpci_release:
469 *	@inode: inode to board
470 *	@file: file handle to board
471 *
472 *	The watchdog has a configurable API. There is a religious dispute
473 *	between people who want their watchdog to be able to shut down and
474 *	those who want to be sure if the watchdog manager dies the machine
475 *	reboots. In the former case we disable the counters, in the latter
476 *	case you have to open it again very soon.
477 */
478
479static int wdtpci_release(struct inode *inode, struct file *file)
480{
481	if (expect_close == 42) {
482		wdtpci_stop();
483	} else {
484		pr_crit("Unexpected close, not stopping timer!\n");
485		wdtpci_ping();
486	}
487	expect_close = 0;
488	clear_bit(0, &open_lock);
489	return 0;
490}
491
492/**
493 *	wdtpci_temp_read:
494 *	@file: file handle to the watchdog board
495 *	@buf: buffer to write 1 byte into
496 *	@count: length of buffer
497 *	@ptr: offset (no seek allowed)
498 *
499 *	Read reports the temperature in degrees Fahrenheit. The API is in
500 *	fahrenheit. It was designed by an imperial measurement luddite.
501 */
502
503static ssize_t wdtpci_temp_read(struct file *file, char __user *buf,
504						size_t count, loff_t *ptr)
505{
506	int temperature;
507
508	if (wdtpci_get_temperature(&temperature))
509		return -EFAULT;
510
511	if (copy_to_user(buf, &temperature, 1))
512		return -EFAULT;
513
514	return 1;
515}
516
517/**
518 *	wdtpci_temp_open:
519 *	@inode: inode of device
520 *	@file: file handle to device
521 *
522 *	The temperature device has been opened.
523 */
524
525static int wdtpci_temp_open(struct inode *inode, struct file *file)
526{
527	return nonseekable_open(inode, file);
528}
529
530/**
531 *	wdtpci_temp_release:
532 *	@inode: inode to board
533 *	@file: file handle to board
534 *
535 *	The temperature device has been closed.
536 */
537
538static int wdtpci_temp_release(struct inode *inode, struct file *file)
539{
540	return 0;
541}
542
543/**
544 *	notify_sys:
545 *	@this: our notifier block
546 *	@code: the event being reported
547 *	@unused: unused
548 *
549 *	Our notifier is called on system shutdowns. We want to turn the card
550 *	off at reboot otherwise the machine will reboot again during memory
551 *	test or worse yet during the following fsck. This would suck, in fact
552 *	trust me - if it happens it does suck.
553 */
554
555static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
556							void *unused)
557{
558	if (code == SYS_DOWN || code == SYS_HALT)
559		wdtpci_stop();
560	return NOTIFY_DONE;
561}
562
563/*
564 *	Kernel Interfaces
565 */
566
567
568static const struct file_operations wdtpci_fops = {
569	.owner		= THIS_MODULE,
570	.llseek		= no_llseek,
571	.write		= wdtpci_write,
572	.unlocked_ioctl	= wdtpci_ioctl,
573	.open		= wdtpci_open,
574	.release	= wdtpci_release,
575};
576
577static struct miscdevice wdtpci_miscdev = {
578	.minor	= WATCHDOG_MINOR,
579	.name	= "watchdog",
580	.fops	= &wdtpci_fops,
581};
582
583static const struct file_operations wdtpci_temp_fops = {
584	.owner		= THIS_MODULE,
585	.llseek		= no_llseek,
586	.read		= wdtpci_temp_read,
587	.open		= wdtpci_temp_open,
588	.release	= wdtpci_temp_release,
589};
590
591static struct miscdevice temp_miscdev = {
592	.minor	= TEMP_MINOR,
593	.name	= "temperature",
594	.fops	= &wdtpci_temp_fops,
595};
596
597/*
598 *	The WDT card needs to learn about soft shutdowns in order to
599 *	turn the timebomb registers off.
600 */
601
602static struct notifier_block wdtpci_notifier = {
603	.notifier_call = wdtpci_notify_sys,
604};
605
606
607static int wdtpci_init_one(struct pci_dev *dev,
608					const struct pci_device_id *ent)
609{
610	int ret = -EIO;
611
612	dev_count++;
613	if (dev_count > 1) {
614		pr_err("This driver only supports one device\n");
615		return -ENODEV;
616	}
617
618	if (type != 500 && type != 501) {
619		pr_err("unknown card type '%d'\n", type);
620		return -ENODEV;
621	}
622
623	if (pci_enable_device(dev)) {
624		pr_err("Not possible to enable PCI Device\n");
625		return -ENODEV;
626	}
627
628	if (pci_resource_start(dev, 2) == 0x0000) {
629		pr_err("No I/O-Address for card detected\n");
630		ret = -ENODEV;
631		goto out_pci;
632	}
633
634	if (pci_request_region(dev, 2, "wdt_pci")) {
635		pr_err("I/O address 0x%llx already in use\n",
636		       (unsigned long long)pci_resource_start(dev, 2));
637		goto out_pci;
638	}
639
640	irq = dev->irq;
641	io = pci_resource_start(dev, 2);
642
643	if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED,
644			 "wdt_pci", &wdtpci_miscdev)) {
645		pr_err("IRQ %d is not free\n", irq);
646		goto out_reg;
647	}
648
649	pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n",
650		(unsigned long long)io, irq);
651
652	/* Check that the heartbeat value is within its range;
653	   if not reset to the default */
654	if (wdtpci_set_heartbeat(heartbeat)) {
655		wdtpci_set_heartbeat(WD_TIMO);
656		pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
657			WD_TIMO);
658	}
659
660	ret = register_reboot_notifier(&wdtpci_notifier);
661	if (ret) {
662		pr_err("cannot register reboot notifier (err=%d)\n", ret);
663		goto out_irq;
664	}
665
666	if (type == 501) {
667		ret = misc_register(&temp_miscdev);
668		if (ret) {
669			pr_err("cannot register miscdev on minor=%d (err=%d)\n",
670			       TEMP_MINOR, ret);
671			goto out_rbt;
672		}
673	}
674
675	ret = misc_register(&wdtpci_miscdev);
676	if (ret) {
677		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
678		       WATCHDOG_MINOR, ret);
679		goto out_misc;
680	}
681
682	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
683		heartbeat, nowayout);
684	if (type == 501)
685		pr_info("Fan Tachometer is %s\n",
686			tachometer ? "Enabled" : "Disabled");
687
688	ret = 0;
689out:
690	return ret;
691
692out_misc:
693	if (type == 501)
694		misc_deregister(&temp_miscdev);
695out_rbt:
696	unregister_reboot_notifier(&wdtpci_notifier);
697out_irq:
698	free_irq(irq, &wdtpci_miscdev);
699out_reg:
700	pci_release_region(dev, 2);
701out_pci:
702	pci_disable_device(dev);
703	goto out;
704}
705
706
707static void wdtpci_remove_one(struct pci_dev *pdev)
708{
709	/* here we assume only one device will ever have
710	 * been picked up and registered by probe function */
711	misc_deregister(&wdtpci_miscdev);
712	if (type == 501)
713		misc_deregister(&temp_miscdev);
714	unregister_reboot_notifier(&wdtpci_notifier);
715	free_irq(irq, &wdtpci_miscdev);
716	pci_release_region(pdev, 2);
717	pci_disable_device(pdev);
718	dev_count--;
719}
720
721
722static const struct pci_device_id wdtpci_pci_tbl[] = {
723	{
724		.vendor	   = PCI_VENDOR_ID_ACCESSIO,
725		.device	   = PCI_DEVICE_ID_ACCESSIO_WDG_CSM,
726		.subvendor = PCI_ANY_ID,
727		.subdevice = PCI_ANY_ID,
728	},
729	{ 0, }, /* terminate list */
730};
731MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
732
733
734static struct pci_driver wdtpci_driver = {
735	.name		= "wdt_pci",
736	.id_table	= wdtpci_pci_tbl,
737	.probe		= wdtpci_init_one,
738	.remove		= wdtpci_remove_one,
739};
740
741module_pci_driver(wdtpci_driver);
742
743MODULE_AUTHOR("JP Nollmann, Alan Cox");
744MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
745MODULE_LICENSE("GPL");
746