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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Alan Cox04bedfa2009-03-22 10:46:42 +00002 * Industrial Computer Source WDT501 driver
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
Alan Cox29fa0582008-10-27 15:17:56 +00004 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
5 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
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
Alan Cox9f2d1f02008-08-04 17:55:35 +010027 * Tim Hockin : Added insmod parameters, comment
28 * cleanup, parameterized timeout
29 * Tigran Aivazian : Restructured wdt_init() to handle
30 * failures
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
32 * Matt Domsch : Added nowayout module option
33 */
34
Joe Perches27c766a2012-02-15 15:06:19 -080035#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/interrupt.h>
38#include <linux/module.h>
39#include <linux/moduleparam.h>
40#include <linux/types.h>
41#include <linux/miscdevice.h>
42#include <linux/watchdog.h>
43#include <linux/fs.h>
44#include <linux/ioport.h>
45#include <linux/notifier.h>
46#include <linux/reboot.h>
47#include <linux/init.h>
Alan Cox9f2d1f02008-08-04 17:55:35 +010048#include <linux/io.h>
49#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include "wd501p.h"
52
53static unsigned long wdt_is_open;
54static char expect_close;
55
56/*
57 * Module parameters
58 */
59
60#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
61
62static int heartbeat = WD_TIMO;
63static int wd_heartbeat;
64module_param(heartbeat, int, 0);
Alan Cox9f2d1f02008-08-04 17:55:35 +010065MODULE_PARM_DESC(heartbeat,
66 "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
67 __MODULE_STRING(WD_TIMO) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010069static bool nowayout = WATCHDOG_NOWAYOUT;
70module_param(nowayout, bool, 0);
Alan Cox9f2d1f02008-08-04 17:55:35 +010071MODULE_PARM_DESC(nowayout,
72 "Watchdog cannot be stopped once started (default="
73 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75/* You must set these - there is no sane way to probe for this board. */
Alan Cox9f2d1f02008-08-04 17:55:35 +010076static int io = 0x240;
77static int irq = 11;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Alan Cox01c785d2008-01-09 21:36:01 -080079static DEFINE_SPINLOCK(wdt_lock);
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081module_param(io, int, 0);
82MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
83module_param(irq, int, 0);
84MODULE_PARM_DESC(irq, "WDT irq (default=11)");
85
Linus Torvalds1da177e2005-04-16 15:20:36 -070086/* Support for the Fan Tachometer on the WDT501-P */
87static int tachometer;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088module_param(tachometer, int, 0);
Alan Cox9f2d1f02008-08-04 17:55:35 +010089MODULE_PARM_DESC(tachometer,
90 "WDT501-P Fan Tachometer support (0=disable, default=0)");
Alan Cox04bedfa2009-03-22 10:46:42 +000091
92static int type = 500;
93module_param(type, int, 0);
94MODULE_PARM_DESC(type,
Randy Dunlap4724ba572010-05-03 11:42:52 -070095 "WDT501-P Card type (500 or 501, default=500)");
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97/*
98 * Programming support
99 */
100
101static void wdt_ctr_mode(int ctr, int mode)
102{
Alan Cox9f2d1f02008-08-04 17:55:35 +0100103 ctr <<= 6;
104 ctr |= 0x30;
105 ctr |= (mode << 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 outb_p(ctr, WDT_CR);
107}
108
109static void wdt_ctr_load(int ctr, int val)
110{
111 outb_p(val&0xFF, WDT_COUNT0+ctr);
112 outb_p(val>>8, WDT_COUNT0+ctr);
113}
114
115/**
116 * wdt_start:
117 *
118 * Start the watchdog driver.
119 */
120
121static int wdt_start(void)
122{
Alan Cox01c785d2008-01-09 21:36:01 -0800123 unsigned long flags;
124 spin_lock_irqsave(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 inb_p(WDT_DC); /* Disable watchdog */
Alan Cox9f2d1f02008-08-04 17:55:35 +0100126 wdt_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
127 Square Wave Generator */
128 wdt_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
129 Rate Generator */
130 wdt_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
131 Pulse on Terminal Count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 wdt_ctr_load(0, 8948); /* Count at 100Hz */
Alan Cox9f2d1f02008-08-04 17:55:35 +0100133 wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */
134 wdt_ctr_load(2, 65535); /* Length of reset pulse */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 outb_p(0, WDT_DC); /* Enable watchdog */
Alan Cox01c785d2008-01-09 21:36:01 -0800136 spin_unlock_irqrestore(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 return 0;
138}
139
140/**
141 * wdt_stop:
142 *
143 * Stop the watchdog driver.
144 */
145
Alan Cox9f2d1f02008-08-04 17:55:35 +0100146static int wdt_stop(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
Alan Cox01c785d2008-01-09 21:36:01 -0800148 unsigned long flags;
149 spin_lock_irqsave(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 /* Turn the card off */
151 inb_p(WDT_DC); /* Disable watchdog */
Alan Cox9f2d1f02008-08-04 17:55:35 +0100152 wdt_ctr_load(2, 0); /* 0 length reset pulses now */
Alan Cox01c785d2008-01-09 21:36:01 -0800153 spin_unlock_irqrestore(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 return 0;
155}
156
157/**
158 * wdt_ping:
159 *
Alan Cox9f2d1f02008-08-04 17:55:35 +0100160 * Reload counter one with the watchdog heartbeat. We don't bother
161 * reloading the cascade counter.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 */
163
Alan Cox04bedfa2009-03-22 10:46:42 +0000164static void wdt_ping(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
Alan Cox01c785d2008-01-09 21:36:01 -0800166 unsigned long flags;
167 spin_lock_irqsave(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 /* Write a watchdog value */
169 inb_p(WDT_DC); /* Disable watchdog */
Alan Cox9f2d1f02008-08-04 17:55:35 +0100170 wdt_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
171 Rate Generator */
172 wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 outb_p(0, WDT_DC); /* Enable watchdog */
Alan Cox01c785d2008-01-09 21:36:01 -0800174 spin_unlock_irqrestore(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175}
176
177/**
178 * wdt_set_heartbeat:
179 * @t: the new heartbeat value that needs to be set.
180 *
Alan Cox9f2d1f02008-08-04 17:55:35 +0100181 * Set a new heartbeat value for the watchdog device. If the heartbeat
182 * value is incorrect we keep the old value and return -EINVAL. If
183 * successful we return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 */
Alan Cox9f2d1f02008-08-04 17:55:35 +0100185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186static int wdt_set_heartbeat(int t)
187{
Alan Cox9f2d1f02008-08-04 17:55:35 +0100188 if (t < 1 || t > 65535)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 return -EINVAL;
190
191 heartbeat = t;
192 wd_heartbeat = t * 100;
193 return 0;
194}
195
196/**
197 * wdt_get_status:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 *
199 * Extract the status information from a WDT watchdog device. There are
200 * several board variants so we have to know which bits are valid. Some
201 * bits default to one and some to zero in order to be maximally painful.
202 *
203 * we then map the bits onto the status ioctl flags.
204 */
205
Alan Cox04bedfa2009-03-22 10:46:42 +0000206static int wdt_get_status(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
Alan Cox01c785d2008-01-09 21:36:01 -0800208 unsigned char new_status;
Alan Cox04bedfa2009-03-22 10:46:42 +0000209 int status = 0;
Alan Cox01c785d2008-01-09 21:36:01 -0800210 unsigned long flags;
211
212 spin_lock_irqsave(&wdt_lock, flags);
213 new_status = inb_p(WDT_SR);
214 spin_unlock_irqrestore(&wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 if (new_status & WDC_SR_ISOI0)
Alan Cox04bedfa2009-03-22 10:46:42 +0000217 status |= WDIOF_EXTERN1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 if (new_status & WDC_SR_ISII1)
Alan Cox04bedfa2009-03-22 10:46:42 +0000219 status |= WDIOF_EXTERN2;
220 if (type == 501) {
221 if (!(new_status & WDC_SR_TGOOD))
222 status |= WDIOF_OVERHEAT;
223 if (!(new_status & WDC_SR_PSUOVER))
224 status |= WDIOF_POWEROVER;
225 if (!(new_status & WDC_SR_PSUUNDR))
226 status |= WDIOF_POWERUNDER;
227 if (tachometer) {
228 if (!(new_status & WDC_SR_FANGOOD))
229 status |= WDIOF_FANFAULT;
230 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 }
Alan Cox04bedfa2009-03-22 10:46:42 +0000232 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233}
234
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235/**
236 * wdt_get_temperature:
237 *
238 * Reports the temperature in degrees Fahrenheit. The API is in
239 * farenheit. It was designed by an imperial measurement luddite.
240 */
241
Alan Cox04bedfa2009-03-22 10:46:42 +0000242static int wdt_get_temperature(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
Alan Cox01c785d2008-01-09 21:36:01 -0800244 unsigned short c;
245 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
Alan Cox01c785d2008-01-09 21:36:01 -0800247 spin_lock_irqsave(&wdt_lock, flags);
248 c = inb_p(WDT_RT);
249 spin_unlock_irqrestore(&wdt_lock, flags);
Alan Cox04bedfa2009-03-22 10:46:42 +0000250 return (c * 11 / 15) + 7;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251}
Alan Cox04bedfa2009-03-22 10:46:42 +0000252
253static void wdt_decode_501(int status)
254{
255 if (!(status & WDC_SR_TGOOD))
Joe Perches27c766a2012-02-15 15:06:19 -0800256 pr_crit("Overheat alarm (%d)\n", inb_p(WDT_RT));
Alan Cox04bedfa2009-03-22 10:46:42 +0000257 if (!(status & WDC_SR_PSUOVER))
Joe Perches27c766a2012-02-15 15:06:19 -0800258 pr_crit("PSU over voltage\n");
Alan Cox04bedfa2009-03-22 10:46:42 +0000259 if (!(status & WDC_SR_PSUUNDR))
Joe Perches27c766a2012-02-15 15:06:19 -0800260 pr_crit("PSU under voltage\n");
Alan Cox04bedfa2009-03-22 10:46:42 +0000261}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263/**
264 * wdt_interrupt:
265 * @irq: Interrupt number
266 * @dev_id: Unused as we don't allow multiple devices.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 *
268 * Handle an interrupt from the board. These are raised when the status
269 * map changes in what the board considers an interesting way. That means
270 * a failure condition occurring.
271 */
272
David Howells7d12e782006-10-05 14:55:46 +0100273static irqreturn_t wdt_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274{
275 /*
276 * Read the status register see what is up and
277 * then printk it.
278 */
Alan Cox01c785d2008-01-09 21:36:01 -0800279 unsigned char status;
280
281 spin_lock(&wdt_lock);
282 status = inb_p(WDT_SR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
Joe Perches27c766a2012-02-15 15:06:19 -0800284 pr_crit("WDT status %d\n", status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Alan Cox04bedfa2009-03-22 10:46:42 +0000286 if (type == 501) {
287 wdt_decode_501(status);
288 if (tachometer) {
289 if (!(status & WDC_SR_FANGOOD))
Joe Perches27c766a2012-02-15 15:06:19 -0800290 pr_crit("Possible fan fault\n");
Alan Cox04bedfa2009-03-22 10:46:42 +0000291 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 }
Ilpo Jarvinen59338d42007-10-23 13:40:54 -0700293 if (!(status & WDC_SR_WCCR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294#ifdef SOFTWARE_REBOOT
295#ifdef ONLY_TESTING
Joe Perches27c766a2012-02-15 15:06:19 -0800296 pr_crit("Would Reboot\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297#else
Joe Perches27c766a2012-02-15 15:06:19 -0800298 pr_crit("Initiating system reboot\n");
Eric W. Biedermanf82567e2005-07-26 11:53:19 -0600299 emergency_restart();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300#endif
301#else
Joe Perches27c766a2012-02-15 15:06:19 -0800302 pr_crit("Reset in 5ms\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303#endif
Ilpo Jarvinen59338d42007-10-23 13:40:54 -0700304 }
Alan Cox01c785d2008-01-09 21:36:01 -0800305 spin_unlock(&wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 return IRQ_HANDLED;
307}
308
309
310/**
311 * wdt_write:
312 * @file: file handle to the watchdog
313 * @buf: buffer to write (unused as data does not matter here
314 * @count: count of bytes
315 * @ppos: pointer to the position to write. No seeks allowed
316 *
317 * A write to a watchdog device is defined as a keepalive signal. Any
318 * write of data will do, as we we don't define content meaning.
319 */
320
Alan Cox9f2d1f02008-08-04 17:55:35 +0100321static ssize_t wdt_write(struct file *file, const char __user *buf,
322 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323{
Alan Cox9f2d1f02008-08-04 17:55:35 +0100324 if (count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 if (!nowayout) {
326 size_t i;
327
328 /* In case it was set long ago */
329 expect_close = 0;
330
331 for (i = 0; i != count; i++) {
332 char c;
333 if (get_user(c, buf + i))
334 return -EFAULT;
335 if (c == 'V')
336 expect_close = 42;
337 }
338 }
339 wdt_ping();
340 }
341 return count;
342}
343
344/**
345 * wdt_ioctl:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 * @file: file handle to the device
347 * @cmd: watchdog command
348 * @arg: argument pointer
349 *
350 * The watchdog API defines a common set of functions for all watchdogs
351 * according to their available features. We only actually usefully support
352 * querying capabilities and current status.
353 */
354
Alan Cox9f2d1f02008-08-04 17:55:35 +0100355static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356{
357 void __user *argp = (void __user *)arg;
358 int __user *p = argp;
359 int new_heartbeat;
360 int status;
361
Andrew Mortonc1bf3ac2010-03-03 11:57:40 -0800362 struct watchdog_info ident = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 .options = WDIOF_SETTIMEOUT|
364 WDIOF_MAGICCLOSE|
365 WDIOF_KEEPALIVEPING,
366 .firmware_version = 1,
367 .identity = "WDT500/501",
368 };
369
370 /* Add options according to the card we have */
371 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
Alan Cox04bedfa2009-03-22 10:46:42 +0000372 if (type == 501) {
373 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
374 WDIOF_POWEROVER);
375 if (tachometer)
376 ident.options |= WDIOF_FANFAULT;
377 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
Alan Cox9f2d1f02008-08-04 17:55:35 +0100379 switch (cmd) {
Alan Cox9f2d1f02008-08-04 17:55:35 +0100380 case WDIOC_GETSUPPORT:
381 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
382 case WDIOC_GETSTATUS:
Alan Cox04bedfa2009-03-22 10:46:42 +0000383 status = wdt_get_status();
Alan Cox9f2d1f02008-08-04 17:55:35 +0100384 return put_user(status, p);
385 case WDIOC_GETBOOTSTATUS:
386 return put_user(0, p);
387 case WDIOC_KEEPALIVE:
388 wdt_ping();
389 return 0;
390 case WDIOC_SETTIMEOUT:
391 if (get_user(new_heartbeat, p))
392 return -EFAULT;
393 if (wdt_set_heartbeat(new_heartbeat))
394 return -EINVAL;
395 wdt_ping();
396 /* Fall */
397 case WDIOC_GETTIMEOUT:
398 return put_user(heartbeat, p);
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000399 default:
400 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 }
402}
403
404/**
405 * wdt_open:
406 * @inode: inode of device
407 * @file: file handle to device
408 *
409 * The watchdog device has been opened. The watchdog device is single
410 * open and on opening we load the counters. Counter zero is a 100Hz
411 * cascade, into counter 1 which downcounts to reboot. When the counter
412 * triggers counter 2 downcounts the length of the reset pulse which
413 * set set to be as long as possible.
414 */
415
416static int wdt_open(struct inode *inode, struct file *file)
417{
Alan Cox9f2d1f02008-08-04 17:55:35 +0100418 if (test_and_set_bit(0, &wdt_is_open))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 return -EBUSY;
420 /*
421 * Activate
422 */
423 wdt_start();
424 return nonseekable_open(inode, file);
425}
426
427/**
428 * wdt_release:
429 * @inode: inode to board
430 * @file: file handle to board
431 *
432 * The watchdog has a configurable API. There is a religious dispute
433 * between people who want their watchdog to be able to shut down and
434 * those who want to be sure if the watchdog manager dies the machine
435 * reboots. In the former case we disable the counters, in the latter
436 * case you have to open it again very soon.
437 */
438
439static int wdt_release(struct inode *inode, struct file *file)
440{
441 if (expect_close == 42) {
442 wdt_stop();
443 clear_bit(0, &wdt_is_open);
444 } else {
Joe Perches27c766a2012-02-15 15:06:19 -0800445 pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 wdt_ping();
447 }
448 expect_close = 0;
449 return 0;
450}
451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452/**
453 * wdt_temp_read:
454 * @file: file handle to the watchdog board
455 * @buf: buffer to write 1 byte into
456 * @count: length of buffer
457 * @ptr: offset (no seek allowed)
458 *
459 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
460 * farenheit. It was designed by an imperial measurement luddite.
461 */
462
Alan Cox9f2d1f02008-08-04 17:55:35 +0100463static ssize_t wdt_temp_read(struct file *file, char __user *buf,
464 size_t count, loff_t *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465{
Alan Cox04bedfa2009-03-22 10:46:42 +0000466 int temperature = wdt_get_temperature();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
Alan Cox9f2d1f02008-08-04 17:55:35 +0100468 if (copy_to_user(buf, &temperature, 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 return -EFAULT;
470
471 return 1;
472}
473
474/**
475 * wdt_temp_open:
476 * @inode: inode of device
477 * @file: file handle to device
478 *
479 * The temperature device has been opened.
480 */
481
482static int wdt_temp_open(struct inode *inode, struct file *file)
483{
484 return nonseekable_open(inode, file);
485}
486
487/**
488 * wdt_temp_release:
489 * @inode: inode to board
490 * @file: file handle to board
491 *
492 * The temperature device has been closed.
493 */
494
495static int wdt_temp_release(struct inode *inode, struct file *file)
496{
497 return 0;
498}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
500/**
501 * notify_sys:
502 * @this: our notifier block
503 * @code: the event being reported
504 * @unused: unused
505 *
506 * Our notifier is called on system shutdowns. We want to turn the card
507 * off at reboot otherwise the machine will reboot again during memory
508 * test or worse yet during the following fsck. This would suck, in fact
509 * trust me - if it happens it does suck.
510 */
511
512static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
513 void *unused)
514{
Alan Cox9f2d1f02008-08-04 17:55:35 +0100515 if (code == SYS_DOWN || code == SYS_HALT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 wdt_stop();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 return NOTIFY_DONE;
518}
519
520/*
521 * Kernel Interfaces
522 */
523
524
Arjan van de Ven62322d22006-07-03 00:24:21 -0700525static const struct file_operations wdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 .owner = THIS_MODULE,
527 .llseek = no_llseek,
528 .write = wdt_write,
Alan Cox9f2d1f02008-08-04 17:55:35 +0100529 .unlocked_ioctl = wdt_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 .open = wdt_open,
531 .release = wdt_release,
532};
533
534static struct miscdevice wdt_miscdev = {
535 .minor = WATCHDOG_MINOR,
536 .name = "watchdog",
537 .fops = &wdt_fops,
538};
539
Arjan van de Ven62322d22006-07-03 00:24:21 -0700540static const struct file_operations wdt_temp_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 .owner = THIS_MODULE,
542 .llseek = no_llseek,
543 .read = wdt_temp_read,
544 .open = wdt_temp_open,
545 .release = wdt_temp_release,
546};
547
548static struct miscdevice temp_miscdev = {
549 .minor = TEMP_MINOR,
550 .name = "temperature",
551 .fops = &wdt_temp_fops,
552};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
554/*
555 * The WDT card needs to learn about soft shutdowns in order to
556 * turn the timebomb registers off.
557 */
558
559static struct notifier_block wdt_notifier = {
560 .notifier_call = wdt_notify_sys,
561};
562
563/**
564 * cleanup_module:
565 *
566 * Unload the watchdog. You cannot do this with any file handles open.
567 * If your watchdog is set to continue ticking on close and you unload
568 * it, well it keeps ticking. We won't get the interrupt but the board
569 * will not touch PC memory so all is fine. You just have to load a new
570 * module in 60 seconds or reboot.
571 */
572
573static void __exit wdt_exit(void)
574{
575 misc_deregister(&wdt_miscdev);
Alan Cox04bedfa2009-03-22 10:46:42 +0000576 if (type == 501)
577 misc_deregister(&temp_miscdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 unregister_reboot_notifier(&wdt_notifier);
579 free_irq(irq, NULL);
Alan Cox9f2d1f02008-08-04 17:55:35 +0100580 release_region(io, 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581}
582
583/**
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000584 * wdt_init:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 *
586 * Set up the WDT watchdog board. All we have to do is grab the
587 * resources we require and bitch if anyone beat us to them.
588 * The open() function will actually kick the board off.
589 */
590
591static int __init wdt_init(void)
592{
593 int ret;
594
Alan Cox04bedfa2009-03-22 10:46:42 +0000595 if (type != 500 && type != 501) {
Joe Perches27c766a2012-02-15 15:06:19 -0800596 pr_err("unknown card type '%d'\n", type);
Alan Cox04bedfa2009-03-22 10:46:42 +0000597 return -ENODEV;
598 }
599
Alan Cox9f2d1f02008-08-04 17:55:35 +0100600 /* Check that the heartbeat value is within it's range;
601 if not reset to the default */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 if (wdt_set_heartbeat(heartbeat)) {
603 wdt_set_heartbeat(WD_TIMO);
Joe Perches27c766a2012-02-15 15:06:19 -0800604 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
605 WD_TIMO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 }
607
608 if (!request_region(io, 8, "wdt501p")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800609 pr_err("I/O address 0x%04x already in use\n", io);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 ret = -EBUSY;
611 goto out;
612 }
613
Yong Zhang86b59122011-09-07 16:10:55 +0800614 ret = request_irq(irq, wdt_interrupt, 0, "wdt501p", NULL);
Alan Cox9f2d1f02008-08-04 17:55:35 +0100615 if (ret) {
Joe Perches27c766a2012-02-15 15:06:19 -0800616 pr_err("IRQ %d is not free\n", irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 goto outreg;
618 }
619
620 ret = register_reboot_notifier(&wdt_notifier);
Alan Cox9f2d1f02008-08-04 17:55:35 +0100621 if (ret) {
Joe Perches27c766a2012-02-15 15:06:19 -0800622 pr_err("cannot register reboot notifier (err=%d)\n", ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 goto outirq;
624 }
625
Alan Cox04bedfa2009-03-22 10:46:42 +0000626 if (type == 501) {
627 ret = misc_register(&temp_miscdev);
628 if (ret) {
Joe Perches27c766a2012-02-15 15:06:19 -0800629 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
630 TEMP_MINOR, ret);
Alan Cox04bedfa2009-03-22 10:46:42 +0000631 goto outrbt;
632 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
635 ret = misc_register(&wdt_miscdev);
636 if (ret) {
Joe Perches27c766a2012-02-15 15:06:19 -0800637 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
638 WATCHDOG_MINOR, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 goto outmisc;
640 }
641
Joe Perches27c766a2012-02-15 15:06:19 -0800642 pr_info("WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 io, irq, heartbeat, nowayout);
Alan Cox04bedfa2009-03-22 10:46:42 +0000644 if (type == 501)
Joe Perches27c766a2012-02-15 15:06:19 -0800645 pr_info("Fan Tachometer is %s\n",
646 tachometer ? "Enabled" : "Disabled");
Alan Cox04bedfa2009-03-22 10:46:42 +0000647 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649outmisc:
Alan Cox04bedfa2009-03-22 10:46:42 +0000650 if (type == 501)
651 misc_deregister(&temp_miscdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652outrbt:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 unregister_reboot_notifier(&wdt_notifier);
654outirq:
655 free_irq(irq, NULL);
656outreg:
Alan Cox9f2d1f02008-08-04 17:55:35 +0100657 release_region(io, 8);
Alan Cox04bedfa2009-03-22 10:46:42 +0000658out:
659 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660}
661
662module_init(wdt_init);
663module_exit(wdt_exit);
664
665MODULE_AUTHOR("Alan Cox");
666MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
667MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
668MODULE_ALIAS_MISCDEV(TEMP_MINOR);
669MODULE_LICENSE("GPL");