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Sven Anders485ae772006-08-24 17:11:50 +02001/*
2 * SMsC 37B787 Watchdog Timer driver for Linux 2.6.x.x
3 *
Alan Cox29fa0582008-10-27 15:17:56 +00004 * Based on acquirewdt.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +00005 * and some other existing drivers
Sven Anders485ae772006-08-24 17:11:50 +02006 *
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.
Wim Van Sebroeck8386c8c2006-09-02 19:32:26 +020011 *
Sven Anders485ae772006-08-24 17:11:50 +020012 * The authors do NOT admit liability nor provide warranty for
13 * any of this software. This material is provided "AS-IS" in
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000014 * the hope that it may be useful for others.
Sven Anders485ae772006-08-24 17:11:50 +020015 *
16 * (C) Copyright 2003-2006 Sven Anders <anders@anduras.de>
17 *
18 * History:
19 * 2003 - Created version 1.0 for Linux 2.4.x.
20 * 2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE
Alan Cox59846792008-05-19 14:09:00 +010021 * features. Released version 1.1
Sven Anders485ae772006-08-24 17:11:50 +020022 *
23 * Theory of operation:
24 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000025 * A Watchdog Timer (WDT) is a hardware circuit that can
26 * reset the computer system in case of a software fault.
27 * You probably knew that already.
Sven Anders485ae772006-08-24 17:11:50 +020028 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000029 * Usually a userspace daemon will notify the kernel WDT driver
30 * via the /dev/watchdog special device file that userspace is
31 * still alive, at regular intervals. When such a notification
32 * occurs, the driver will usually tell the hardware watchdog
33 * that everything is in order, and that the watchdog should wait
34 * for yet another little while to reset the system.
35 * If userspace fails (RAM error, kernel bug, whatever), the
36 * notifications cease to occur, and the hardware watchdog will
37 * reset the system (causing a reboot) after the timeout occurs.
Sven Anders485ae772006-08-24 17:11:50 +020038 *
39 * Create device with:
40 * mknod /dev/watchdog c 10 130
41 *
42 * For an example userspace keep-alive daemon, see:
Paul Bolle395cf962011-08-15 02:02:26 +020043 * Documentation/watchdog/wdt.txt
Sven Anders485ae772006-08-24 17:11:50 +020044 */
45
Joe Perches27c766a2012-02-15 15:06:19 -080046#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
Sven Anders485ae772006-08-24 17:11:50 +020048#include <linux/module.h>
49#include <linux/moduleparam.h>
50#include <linux/types.h>
51#include <linux/miscdevice.h>
52#include <linux/watchdog.h>
53#include <linux/delay.h>
54#include <linux/fs.h>
55#include <linux/ioport.h>
56#include <linux/notifier.h>
57#include <linux/reboot.h>
58#include <linux/init.h>
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +020059#include <linux/spinlock.h>
Alan Cox59846792008-05-19 14:09:00 +010060#include <linux/io.h>
61#include <linux/uaccess.h>
Sven Anders485ae772006-08-24 17:11:50 +020062
Sven Anders485ae772006-08-24 17:11:50 +020063
64/* enable support for minutes as units? */
65/* (does not always work correctly, so disabled by default!) */
66#define SMSC_SUPPORT_MINUTES
67#undef SMSC_SUPPORT_MINUTES
68
69#define MAX_TIMEOUT 255
70
71#define UNIT_SECOND 0
72#define UNIT_MINUTE 1
73
Alan Cox59846792008-05-19 14:09:00 +010074#define VERSION "1.1"
Sven Anders485ae772006-08-24 17:11:50 +020075
Alan Cox59846792008-05-19 14:09:00 +010076#define IOPORT 0x3F0
Sven Anders485ae772006-08-24 17:11:50 +020077#define IOPORT_SIZE 2
Alan Cox59846792008-05-19 14:09:00 +010078#define IODEV_NO 8
Sven Anders485ae772006-08-24 17:11:50 +020079
Alan Cox59846792008-05-19 14:09:00 +010080static int unit = UNIT_SECOND; /* timer's unit */
81static int timeout = 60; /* timeout value: default is 60 "units" */
82static unsigned long timer_enabled; /* is the timer enabled? */
Sven Anders485ae772006-08-24 17:11:50 +020083
84static char expect_close; /* is the close expected? */
85
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070086static DEFINE_SPINLOCK(io_lock);/* to guard the watchdog from io races */
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +020087
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010088static bool nowayout = WATCHDOG_NOWAYOUT;
Sven Anders485ae772006-08-24 17:11:50 +020089
90/* -- Low level function ----------------------------------------*/
91
92/* unlock the IO chip */
93
94static inline void open_io_config(void)
95{
Alan Cox59846792008-05-19 14:09:00 +010096 outb(0x55, IOPORT);
Sven Anders485ae772006-08-24 17:11:50 +020097 mdelay(1);
Alan Cox59846792008-05-19 14:09:00 +010098 outb(0x55, IOPORT);
Sven Anders485ae772006-08-24 17:11:50 +020099}
100
101/* lock the IO chip */
102static inline void close_io_config(void)
103{
Alan Cox59846792008-05-19 14:09:00 +0100104 outb(0xAA, IOPORT);
Sven Anders485ae772006-08-24 17:11:50 +0200105}
106
107/* select the IO device */
108static inline void select_io_device(unsigned char devno)
109{
Alan Cox59846792008-05-19 14:09:00 +0100110 outb(0x07, IOPORT);
111 outb(devno, IOPORT+1);
Sven Anders485ae772006-08-24 17:11:50 +0200112}
113
114/* write to the control register */
115static inline void write_io_cr(unsigned char reg, unsigned char data)
116{
Alan Cox59846792008-05-19 14:09:00 +0100117 outb(reg, IOPORT);
118 outb(data, IOPORT+1);
Sven Anders485ae772006-08-24 17:11:50 +0200119}
120
121/* read from the control register */
122static inline char read_io_cr(unsigned char reg)
123{
Alan Cox59846792008-05-19 14:09:00 +0100124 outb(reg, IOPORT);
125 return inb(IOPORT+1);
Sven Anders485ae772006-08-24 17:11:50 +0200126}
127
128/* -- Medium level functions ------------------------------------*/
129
130static inline void gpio_bit12(unsigned char reg)
131{
Alan Cox59846792008-05-19 14:09:00 +0100132 /* -- General Purpose I/O Bit 1.2 --
133 * Bit 0, In/Out: 0 = Output, 1 = Input
134 * Bit 1, Polarity: 0 = No Invert, 1 = Invert
135 * Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
136 * Bit 3/4, Function select: 00 = GPI/O, 01 = WDT, 10 = P17,
137 * 11 = Either Edge Triggered Intr. 2
138 * Bit 5/6 (Reserved)
139 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
140 */
141 write_io_cr(0xE2, reg);
Sven Anders485ae772006-08-24 17:11:50 +0200142}
143
144static inline void gpio_bit13(unsigned char reg)
145{
Alan Cox59846792008-05-19 14:09:00 +0100146 /* -- General Purpose I/O Bit 1.3 --
147 * Bit 0, In/Out: 0 = Output, 1 = Input
148 * Bit 1, Polarity: 0 = No Invert, 1 = Invert
149 * Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
150 * Bit 3, Function select: 0 = GPI/O, 1 = LED
151 * Bit 4-6 (Reserved)
152 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
153 */
154 write_io_cr(0xE3, reg);
Sven Anders485ae772006-08-24 17:11:50 +0200155}
156
157static inline void wdt_timer_units(unsigned char new_units)
158{
Alan Cox59846792008-05-19 14:09:00 +0100159 /* -- Watchdog timer units --
160 * Bit 0-6 (Reserved)
161 * Bit 7, WDT Time-out Value Units Select
162 * (0 = Minutes, 1 = Seconds)
163 */
164 write_io_cr(0xF1, new_units);
Sven Anders485ae772006-08-24 17:11:50 +0200165}
166
167static inline void wdt_timeout_value(unsigned char new_timeout)
168{
Alan Cox59846792008-05-19 14:09:00 +0100169 /* -- Watchdog Timer Time-out Value --
170 * Bit 0-7 Binary coded units (0=Disabled, 1..255)
171 */
172 write_io_cr(0xF2, new_timeout);
Sven Anders485ae772006-08-24 17:11:50 +0200173}
174
175static inline void wdt_timer_conf(unsigned char conf)
176{
Alan Cox59846792008-05-19 14:09:00 +0100177 /* -- Watchdog timer configuration --
178 * Bit 0 Joystick enable: 0* = No Reset, 1 = Reset WDT upon
179 * Gameport I/O
180 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
181 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
182 * Bit 3 Reset the timer
183 * (Wrong in SMsC documentation? Given as: PowerLED Timout
184 * Enabled)
185 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
186 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
187 */
188 write_io_cr(0xF3, conf);
Sven Anders485ae772006-08-24 17:11:50 +0200189}
190
191static inline void wdt_timer_ctrl(unsigned char reg)
192{
Alan Cox59846792008-05-19 14:09:00 +0100193 /* -- Watchdog timer control --
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300194 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
Alan Cox59846792008-05-19 14:09:00 +0100195 * Bit 1 Power LED Toggle: 0 = Disable Toggle, 1 = Toggle at 1 Hz
196 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
197 * Bit 3 P20 Force Timeout enabled:
198 * 0 = P20 activity does not generate the WD timeout event
199 * 1 = P20 Allows rising edge of P20, from the keyboard
200 * controller, to force the WD timeout event.
201 * Bit 4 (Reserved)
202 * -- Soft power management --
203 * Bit 5 Stop Counter: 1 = Stop software power down counter
204 * set via register 0xB8, (self-cleaning)
205 * (Upon read: 0 = Counter running, 1 = Counter stopped)
206 * Bit 6 Restart Counter: 1 = Restart software power down counter
207 * set via register 0xB8, (self-cleaning)
208 * Bit 7 SPOFF: 1 = Force software power down (self-cleaning)
209 */
210 write_io_cr(0xF4, reg);
Sven Anders485ae772006-08-24 17:11:50 +0200211}
212
213/* -- Higher level functions ------------------------------------*/
214
215/* initialize watchdog */
216
217static void wb_smsc_wdt_initialize(void)
218{
Alan Cox59846792008-05-19 14:09:00 +0100219 unsigned char old;
Sven Anders485ae772006-08-24 17:11:50 +0200220
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200221 spin_lock(&io_lock);
Alan Cox59846792008-05-19 14:09:00 +0100222 open_io_config();
223 select_io_device(IODEV_NO);
Sven Anders485ae772006-08-24 17:11:50 +0200224
Alan Cox59846792008-05-19 14:09:00 +0100225 /* enable the watchdog */
226 gpio_bit13(0x08); /* Select pin 80 = LED not GPIO */
227 gpio_bit12(0x0A); /* Set pin 79 = WDT not
228 GPIO/Output/Polarity=Invert */
229 /* disable the timeout */
230 wdt_timeout_value(0);
Sven Anders485ae772006-08-24 17:11:50 +0200231
Alan Cox59846792008-05-19 14:09:00 +0100232 /* reset control register */
233 wdt_timer_ctrl(0x00);
Sven Anders485ae772006-08-24 17:11:50 +0200234
Alan Cox59846792008-05-19 14:09:00 +0100235 /* reset configuration register */
Sven Anders485ae772006-08-24 17:11:50 +0200236 wdt_timer_conf(0x00);
237
Alan Cox59846792008-05-19 14:09:00 +0100238 /* read old (timer units) register */
239 old = read_io_cr(0xF1) & 0x7F;
240 if (unit == UNIT_SECOND)
241 old |= 0x80; /* set to seconds */
Sven Anders485ae772006-08-24 17:11:50 +0200242
Alan Cox59846792008-05-19 14:09:00 +0100243 /* set the watchdog timer units */
244 wdt_timer_units(old);
Sven Anders485ae772006-08-24 17:11:50 +0200245
Alan Cox59846792008-05-19 14:09:00 +0100246 close_io_config();
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200247 spin_unlock(&io_lock);
Sven Anders485ae772006-08-24 17:11:50 +0200248}
249
250/* shutdown the watchdog */
251
252static void wb_smsc_wdt_shutdown(void)
253{
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200254 spin_lock(&io_lock);
Alan Cox59846792008-05-19 14:09:00 +0100255 open_io_config();
256 select_io_device(IODEV_NO);
Sven Anders485ae772006-08-24 17:11:50 +0200257
Alan Cox59846792008-05-19 14:09:00 +0100258 /* disable the watchdog */
259 gpio_bit13(0x09);
260 gpio_bit12(0x09);
Sven Anders485ae772006-08-24 17:11:50 +0200261
Alan Cox59846792008-05-19 14:09:00 +0100262 /* reset watchdog config register */
Sven Anders485ae772006-08-24 17:11:50 +0200263 wdt_timer_conf(0x00);
264
Alan Cox59846792008-05-19 14:09:00 +0100265 /* reset watchdog control register */
266 wdt_timer_ctrl(0x00);
Sven Anders485ae772006-08-24 17:11:50 +0200267
Alan Cox59846792008-05-19 14:09:00 +0100268 /* disable timeout */
269 wdt_timeout_value(0x00);
Sven Anders485ae772006-08-24 17:11:50 +0200270
Alan Cox59846792008-05-19 14:09:00 +0100271 close_io_config();
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200272 spin_unlock(&io_lock);
Sven Anders485ae772006-08-24 17:11:50 +0200273}
274
275/* set timeout => enable watchdog */
276
277static void wb_smsc_wdt_set_timeout(unsigned char new_timeout)
278{
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200279 spin_lock(&io_lock);
Alan Cox59846792008-05-19 14:09:00 +0100280 open_io_config();
281 select_io_device(IODEV_NO);
Sven Anders485ae772006-08-24 17:11:50 +0200282
Alan Cox59846792008-05-19 14:09:00 +0100283 /* set Power LED to blink, if we enable the timeout */
284 wdt_timer_ctrl((new_timeout == 0) ? 0x00 : 0x02);
Sven Anders485ae772006-08-24 17:11:50 +0200285
Alan Cox59846792008-05-19 14:09:00 +0100286 /* set timeout value */
287 wdt_timeout_value(new_timeout);
Sven Anders485ae772006-08-24 17:11:50 +0200288
Alan Cox59846792008-05-19 14:09:00 +0100289 close_io_config();
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200290 spin_unlock(&io_lock);
Sven Anders485ae772006-08-24 17:11:50 +0200291}
292
293/* get timeout */
294
295static unsigned char wb_smsc_wdt_get_timeout(void)
296{
Alan Cox59846792008-05-19 14:09:00 +0100297 unsigned char set_timeout;
Sven Anders485ae772006-08-24 17:11:50 +0200298
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200299 spin_lock(&io_lock);
Alan Cox59846792008-05-19 14:09:00 +0100300 open_io_config();
301 select_io_device(IODEV_NO);
302 set_timeout = read_io_cr(0xF2);
303 close_io_config();
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200304 spin_unlock(&io_lock);
Sven Anders485ae772006-08-24 17:11:50 +0200305
Alan Cox59846792008-05-19 14:09:00 +0100306 return set_timeout;
Sven Anders485ae772006-08-24 17:11:50 +0200307}
308
309/* disable watchdog */
310
311static void wb_smsc_wdt_disable(void)
312{
Alan Cox59846792008-05-19 14:09:00 +0100313 /* set the timeout to 0 to disable the watchdog */
314 wb_smsc_wdt_set_timeout(0);
Sven Anders485ae772006-08-24 17:11:50 +0200315}
316
317/* enable watchdog by setting the current timeout */
318
319static void wb_smsc_wdt_enable(void)
320{
Alan Cox59846792008-05-19 14:09:00 +0100321 /* set the current timeout... */
322 wb_smsc_wdt_set_timeout(timeout);
Sven Anders485ae772006-08-24 17:11:50 +0200323}
324
325/* reset the timer */
326
327static void wb_smsc_wdt_reset_timer(void)
328{
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200329 spin_lock(&io_lock);
Alan Cox59846792008-05-19 14:09:00 +0100330 open_io_config();
331 select_io_device(IODEV_NO);
Sven Anders485ae772006-08-24 17:11:50 +0200332
Alan Cox59846792008-05-19 14:09:00 +0100333 /* reset the timer */
Sven Anders485ae772006-08-24 17:11:50 +0200334 wdt_timeout_value(timeout);
335 wdt_timer_conf(0x08);
336
Alan Cox59846792008-05-19 14:09:00 +0100337 close_io_config();
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200338 spin_unlock(&io_lock);
Sven Anders485ae772006-08-24 17:11:50 +0200339}
340
341/* return, if the watchdog is enabled (timeout is set...) */
342
343static int wb_smsc_wdt_status(void)
344{
345 return (wb_smsc_wdt_get_timeout() == 0) ? 0 : WDIOF_KEEPALIVEPING;
346}
347
348
349/* -- File operations -------------------------------------------*/
350
351/* open => enable watchdog and set initial timeout */
352
353static int wb_smsc_wdt_open(struct inode *inode, struct file *file)
354{
355 /* /dev/watchdog can only be opened once */
356
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200357 if (test_and_set_bit(0, &timer_enabled))
Sven Anders485ae772006-08-24 17:11:50 +0200358 return -EBUSY;
359
360 if (nowayout)
361 __module_get(THIS_MODULE);
362
363 /* Reload and activate timer */
Sven Anders485ae772006-08-24 17:11:50 +0200364 wb_smsc_wdt_enable();
365
Joe Perches27c766a2012-02-15 15:06:19 -0800366 pr_info("Watchdog enabled. Timeout set to %d %s\n",
Alan Cox59846792008-05-19 14:09:00 +0100367 timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
Sven Anders485ae772006-08-24 17:11:50 +0200368
369 return nonseekable_open(inode, file);
370}
371
372/* close => shut off the timer */
373
374static int wb_smsc_wdt_release(struct inode *inode, struct file *file)
375{
376 /* Shut off the timer. */
377
378 if (expect_close == 42) {
Alan Cox59846792008-05-19 14:09:00 +0100379 wb_smsc_wdt_disable();
Joe Perches27c766a2012-02-15 15:06:19 -0800380 pr_info("Watchdog disabled, sleeping again...\n");
Sven Anders485ae772006-08-24 17:11:50 +0200381 } else {
Joe Perches27c766a2012-02-15 15:06:19 -0800382 pr_crit("Unexpected close, not stopping watchdog!\n");
Sven Anders485ae772006-08-24 17:11:50 +0200383 wb_smsc_wdt_reset_timer();
384 }
385
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200386 clear_bit(0, &timer_enabled);
Sven Anders485ae772006-08-24 17:11:50 +0200387 expect_close = 0;
388 return 0;
389}
390
391/* write => update the timer to keep the machine alive */
392
393static ssize_t wb_smsc_wdt_write(struct file *file, const char __user *data,
394 size_t len, loff_t *ppos)
395{
396 /* See if we got the magic character 'V' and reload the timer */
397 if (len) {
398 if (!nowayout) {
399 size_t i;
400
401 /* reset expect flag */
402 expect_close = 0;
403
Alan Cox59846792008-05-19 14:09:00 +0100404 /* scan to see whether or not we got the
405 magic character */
Sven Anders485ae772006-08-24 17:11:50 +0200406 for (i = 0; i != len; i++) {
407 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000408 if (get_user(c, data + i))
Sven Anders485ae772006-08-24 17:11:50 +0200409 return -EFAULT;
410 if (c == 'V')
411 expect_close = 42;
412 }
413 }
414
415 /* someone wrote to us, we should reload the timer */
416 wb_smsc_wdt_reset_timer();
417 }
418 return len;
419}
420
421/* ioctl => control interface */
422
Alan Cox59846792008-05-19 14:09:00 +0100423static long wb_smsc_wdt_ioctl(struct file *file,
424 unsigned int cmd, unsigned long arg)
Sven Anders485ae772006-08-24 17:11:50 +0200425{
426 int new_timeout;
427
428 union {
429 struct watchdog_info __user *ident;
430 int __user *i;
431 } uarg;
432
Alan Cox59846792008-05-19 14:09:00 +0100433 static const struct watchdog_info ident = {
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000434 .options = WDIOF_KEEPALIVEPING |
Alan Cox59846792008-05-19 14:09:00 +0100435 WDIOF_SETTIMEOUT |
Sven Anders485ae772006-08-24 17:11:50 +0200436 WDIOF_MAGICCLOSE,
437 .firmware_version = 0,
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000438 .identity = "SMsC 37B787 Watchdog",
Sven Anders485ae772006-08-24 17:11:50 +0200439 };
440
441 uarg.i = (int __user *)arg;
442
443 switch (cmd) {
Alan Cox59846792008-05-19 14:09:00 +0100444 case WDIOC_GETSUPPORT:
445 return copy_to_user(uarg.ident, &ident, sizeof(ident))
446 ? -EFAULT : 0;
447 case WDIOC_GETSTATUS:
448 return put_user(wb_smsc_wdt_status(), uarg.i);
449 case WDIOC_GETBOOTSTATUS:
450 return put_user(0, uarg.i);
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000451 case WDIOC_SETOPTIONS:
452 {
453 int options, retval = -EINVAL;
454
455 if (get_user(options, uarg.i))
456 return -EFAULT;
457
458 if (options & WDIOS_DISABLECARD) {
459 wb_smsc_wdt_disable();
460 retval = 0;
461 }
462 if (options & WDIOS_ENABLECARD) {
463 wb_smsc_wdt_enable();
464 retval = 0;
465 }
466 return retval;
467 }
Alan Cox59846792008-05-19 14:09:00 +0100468 case WDIOC_KEEPALIVE:
469 wb_smsc_wdt_reset_timer();
470 return 0;
471 case WDIOC_SETTIMEOUT:
472 if (get_user(new_timeout, uarg.i))
473 return -EFAULT;
474 /* the API states this is given in secs */
475 if (unit == UNIT_MINUTE)
476 new_timeout /= 60;
477 if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
478 return -EINVAL;
479 timeout = new_timeout;
480 wb_smsc_wdt_set_timeout(timeout);
481 /* fall through and return the new timeout... */
482 case WDIOC_GETTIMEOUT:
483 new_timeout = timeout;
484 if (unit == UNIT_MINUTE)
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000485 new_timeout *= 60;
Alan Cox59846792008-05-19 14:09:00 +0100486 return put_user(new_timeout, uarg.i);
Alan Cox59846792008-05-19 14:09:00 +0100487 default:
488 return -ENOTTY;
Sven Anders485ae772006-08-24 17:11:50 +0200489 }
490}
491
492/* -- Notifier funtions -----------------------------------------*/
493
Alan Cox59846792008-05-19 14:09:00 +0100494static int wb_smsc_wdt_notify_sys(struct notifier_block *this,
495 unsigned long code, void *unused)
Sven Anders485ae772006-08-24 17:11:50 +0200496{
Alan Cox59846792008-05-19 14:09:00 +0100497 if (code == SYS_DOWN || code == SYS_HALT) {
498 /* set timeout to 0, to avoid possible race-condition */
499 timeout = 0;
Sven Anders485ae772006-08-24 17:11:50 +0200500 wb_smsc_wdt_disable();
501 }
502 return NOTIFY_DONE;
503}
504
505/* -- Module's structures ---------------------------------------*/
506
Alan Cox59846792008-05-19 14:09:00 +0100507static const struct file_operations wb_smsc_wdt_fops = {
508 .owner = THIS_MODULE,
Sven Anders485ae772006-08-24 17:11:50 +0200509 .llseek = no_llseek,
510 .write = wb_smsc_wdt_write,
Alan Cox59846792008-05-19 14:09:00 +0100511 .unlocked_ioctl = wb_smsc_wdt_ioctl,
Sven Anders485ae772006-08-24 17:11:50 +0200512 .open = wb_smsc_wdt_open,
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200513 .release = wb_smsc_wdt_release,
Sven Anders485ae772006-08-24 17:11:50 +0200514};
515
Alan Cox59846792008-05-19 14:09:00 +0100516static struct notifier_block wb_smsc_wdt_notifier = {
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200517 .notifier_call = wb_smsc_wdt_notify_sys,
Sven Anders485ae772006-08-24 17:11:50 +0200518};
519
Alan Cox59846792008-05-19 14:09:00 +0100520static struct miscdevice wb_smsc_wdt_miscdev = {
Sven Anders485ae772006-08-24 17:11:50 +0200521 .minor = WATCHDOG_MINOR,
522 .name = "watchdog",
523 .fops = &wb_smsc_wdt_fops,
524};
525
526/* -- Module init functions -------------------------------------*/
527
528/* module's "constructor" */
529
530static int __init wb_smsc_wdt_init(void)
531{
532 int ret;
533
Joe Perches27c766a2012-02-15 15:06:19 -0800534 pr_info("SMsC 37B787 watchdog component driver "
535 VERSION " initialising...\n");
Sven Anders485ae772006-08-24 17:11:50 +0200536
537 if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800538 pr_err("Unable to register IO port %#x\n", IOPORT);
Sven Anders485ae772006-08-24 17:11:50 +0200539 ret = -EBUSY;
540 goto out_pnp;
541 }
542
Alan Cox59846792008-05-19 14:09:00 +0100543 /* set new maximum, if it's too big */
544 if (timeout > MAX_TIMEOUT)
545 timeout = MAX_TIMEOUT;
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200546
Alan Cox59846792008-05-19 14:09:00 +0100547 /* init the watchdog timer */
548 wb_smsc_wdt_initialize();
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200549
Sven Anders485ae772006-08-24 17:11:50 +0200550 ret = register_reboot_notifier(&wb_smsc_wdt_notifier);
551 if (ret) {
Joe Perches27c766a2012-02-15 15:06:19 -0800552 pr_err("Unable to register reboot notifier err = %d\n", ret);
Sven Anders485ae772006-08-24 17:11:50 +0200553 goto out_io;
554 }
555
556 ret = misc_register(&wb_smsc_wdt_miscdev);
557 if (ret) {
Joe Perches27c766a2012-02-15 15:06:19 -0800558 pr_err("Unable to register miscdev on minor %d\n",
559 WATCHDOG_MINOR);
Sven Anders485ae772006-08-24 17:11:50 +0200560 goto out_rbt;
561 }
562
Alan Cox59846792008-05-19 14:09:00 +0100563 /* output info */
Joe Perches27c766a2012-02-15 15:06:19 -0800564 pr_info("Timeout set to %d %s\n",
Alan Cox59846792008-05-19 14:09:00 +0100565 timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
Joe Perches27c766a2012-02-15 15:06:19 -0800566 pr_info("Watchdog initialized and sleeping (nowayout=%d)...\n",
567 nowayout);
Sven Anders485ae772006-08-24 17:11:50 +0200568out_clean:
569 return ret;
570
571out_rbt:
572 unregister_reboot_notifier(&wb_smsc_wdt_notifier);
573
574out_io:
575 release_region(IOPORT, IOPORT_SIZE);
576
577out_pnp:
578 goto out_clean;
Wim Van Sebroeck8386c8c2006-09-02 19:32:26 +0200579}
Sven Anders485ae772006-08-24 17:11:50 +0200580
581/* module's "destructor" */
582
583static void __exit wb_smsc_wdt_exit(void)
584{
585 /* Stop the timer before we leave */
Alan Cox59846792008-05-19 14:09:00 +0100586 if (!nowayout) {
Sven Anders485ae772006-08-24 17:11:50 +0200587 wb_smsc_wdt_shutdown();
Joe Perches27c766a2012-02-15 15:06:19 -0800588 pr_info("Watchdog disabled\n");
Sven Anders485ae772006-08-24 17:11:50 +0200589 }
590
591 misc_deregister(&wb_smsc_wdt_miscdev);
592 unregister_reboot_notifier(&wb_smsc_wdt_notifier);
593 release_region(IOPORT, IOPORT_SIZE);
594
Joe Perches27c766a2012-02-15 15:06:19 -0800595 pr_info("SMsC 37B787 watchdog component driver removed\n");
Sven Anders485ae772006-08-24 17:11:50 +0200596}
597
598module_init(wb_smsc_wdt_init);
599module_exit(wb_smsc_wdt_exit);
600
601MODULE_AUTHOR("Sven Anders <anders@anduras.de>");
Alan Cox59846792008-05-19 14:09:00 +0100602MODULE_DESCRIPTION("Driver for SMsC 37B787 watchdog component (Version "
603 VERSION ")");
Sven Anders485ae772006-08-24 17:11:50 +0200604MODULE_LICENSE("GPL");
605
606MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
607
608#ifdef SMSC_SUPPORT_MINUTES
609module_param(unit, int, 0);
Alan Cox59846792008-05-19 14:09:00 +0100610MODULE_PARM_DESC(unit,
611 "set unit to use, 0=seconds or 1=minutes, default is 0");
Sven Anders485ae772006-08-24 17:11:50 +0200612#endif
613
Wim Van Sebroeckaa1fd4d2006-09-02 20:53:19 +0200614module_param(timeout, int, 0);
Sven Anders485ae772006-08-24 17:11:50 +0200615MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");
616
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +0100617module_param(nowayout, bool, 0);
Alan Cox59846792008-05-19 14:09:00 +0100618MODULE_PARM_DESC(nowayout,
619 "Watchdog cannot be stopped once started (default="
620 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");