blob: 2dfc27559bf74cadaada73af766c7d1987fd2feb [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * MachZ ZF-Logic Watchdog Timer driver for Linux
3 *
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 *
10 * The author does NOT admit liability nor provide warranty for
11 * any of this software. This material is provided "AS-IS" in
12 * the hope that it may be useful for others.
13 *
14 * Author: Fernando Fuganti <fuganti@conectiva.com.br>
15 *
16 * Based on sbc60xxwdt.c by Jakob Oestergaard
17 *
18 *
19 * We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
20 * following periods:
21 * wd#1 - 2 seconds;
22 * wd#2 - 7.2 ms;
23 * After the expiration of wd#1, it can generate a NMI, SCI, SMI, or
24 * a system RESET and it starts wd#2 that unconditionaly will RESET
25 * the system when the counter reaches zero.
26 *
27 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
28 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
29 */
30
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/types.h>
34#include <linux/timer.h>
35#include <linux/jiffies.h>
36#include <linux/miscdevice.h>
37#include <linux/watchdog.h>
38#include <linux/fs.h>
39#include <linux/ioport.h>
40#include <linux/notifier.h>
41#include <linux/reboot.h>
42#include <linux/init.h>
Alan Cox325ea4d2008-05-19 14:06:59 +010043#include <linux/io.h>
44#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <asm/system.h>
47
48/* ports */
49#define ZF_IOBASE 0x218
50#define INDEX 0x218
51#define DATA_B 0x219
52#define DATA_W 0x21A
53#define DATA_D 0x21A
54
55/* indexes */ /* size */
56#define ZFL_VERSION 0x02 /* 16 */
57#define CONTROL 0x10 /* 16 */
58#define STATUS 0x12 /* 8 */
59#define COUNTER_1 0x0C /* 16 */
60#define COUNTER_2 0x0E /* 8 */
61#define PULSE_LEN 0x0F /* 8 */
62
63/* controls */
64#define ENABLE_WD1 0x0001
65#define ENABLE_WD2 0x0002
66#define RESET_WD1 0x0010
67#define RESET_WD2 0x0020
68#define GEN_SCI 0x0100
69#define GEN_NMI 0x0200
70#define GEN_SMI 0x0400
71#define GEN_RESET 0x0800
72
73
74/* utilities */
75
76#define WD1 0
77#define WD2 1
78
79#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
80#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
81#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
82
83
84static unsigned short zf_readw(unsigned char port)
85{
86 outb(port, INDEX);
87 return inw(DATA_W);
88}
89
90
91MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
92MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
93MODULE_LICENSE("GPL");
94MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
95
Andrey Panin4bfdf372005-07-27 11:43:58 -070096static int nowayout = WATCHDOG_NOWAYOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097module_param(nowayout, int, 0);
Alan Cox325ea4d2008-05-19 14:06:59 +010098MODULE_PARM_DESC(nowayout,
99 "Watchdog cannot be stopped once started (default="
100 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102#define PFX "machzwd"
103
104static struct watchdog_info zf_info = {
105 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
106 .firmware_version = 1,
107 .identity = "ZF-Logic watchdog",
108};
109
110
111/*
112 * action refers to action taken when watchdog resets
113 * 0 = GEN_RESET
114 * 1 = GEN_SMI
115 * 2 = GEN_NMI
116 * 3 = GEN_SCI
117 * defaults to GEN_RESET (0)
118 */
Alan Cox325ea4d2008-05-19 14:06:59 +0100119static int action;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120module_param(action, int, 0);
121MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
122
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100123static void zf_ping(unsigned long data);
124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125static int zf_action = GEN_RESET;
126static unsigned long zf_is_open;
127static char zf_expect_close;
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -0700128static DEFINE_SPINLOCK(zf_port_lock);
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100129static DEFINE_TIMER(zf_timer, zf_ping, 0, 0);
Alan Cox325ea4d2008-05-19 14:06:59 +0100130static unsigned long next_heartbeat;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132
133/* timeout for user land heart beat (10 seconds) */
134#define ZF_USER_TIMEO (HZ*10)
135
136/* timeout for hardware watchdog (~500ms) */
137#define ZF_HW_TIMEO (HZ/2)
138
139/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
140#define ZF_CTIMEOUT 0xffff
141
142#ifndef ZF_DEBUG
143# define dprintk(format, args...)
144#else
Harvey Harrisonfa9363c2008-03-05 18:24:58 -0800145# define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __func__, __LINE__ , ## args)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146#endif
147
148
149static inline void zf_set_status(unsigned char new)
150{
151 zf_writeb(STATUS, new);
152}
153
154
155/* CONTROL register functions */
156
157static inline unsigned short zf_get_control(void)
158{
159 return zf_readw(CONTROL);
160}
161
162static inline void zf_set_control(unsigned short new)
163{
164 zf_writew(CONTROL, new);
165}
166
167
168/* WD#? counter functions */
169/*
170 * Just set counter value
171 */
172
173static inline void zf_set_timer(unsigned short new, unsigned char n)
174{
Alan Cox325ea4d2008-05-19 14:06:59 +0100175 switch (n) {
176 case WD1:
177 zf_writew(COUNTER_1, new);
178 case WD2:
179 zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
180 default:
181 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 }
183}
184
185/*
186 * stop hardware timer
187 */
188static void zf_timer_off(void)
189{
190 unsigned int ctrl_reg = 0;
191 unsigned long flags;
192
193 /* stop internal ping */
194 del_timer_sync(&zf_timer);
195
196 spin_lock_irqsave(&zf_port_lock, flags);
197 /* stop watchdog timer */
198 ctrl_reg = zf_get_control();
199 ctrl_reg |= (ENABLE_WD1|ENABLE_WD2); /* disable wd1 and wd2 */
200 ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
201 zf_set_control(ctrl_reg);
202 spin_unlock_irqrestore(&zf_port_lock, flags);
203
204 printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");
205}
206
207
208/*
209 * start hardware timer
210 */
211static void zf_timer_on(void)
212{
213 unsigned int ctrl_reg = 0;
214 unsigned long flags;
215
216 spin_lock_irqsave(&zf_port_lock, flags);
217
218 zf_writeb(PULSE_LEN, 0xff);
219
220 zf_set_timer(ZF_CTIMEOUT, WD1);
221
222 /* user land ping */
223 next_heartbeat = jiffies + ZF_USER_TIMEO;
224
225 /* start the timer for internal ping */
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100226 mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228 /* start watchdog timer */
229 ctrl_reg = zf_get_control();
230 ctrl_reg |= (ENABLE_WD1|zf_action);
231 zf_set_control(ctrl_reg);
232 spin_unlock_irqrestore(&zf_port_lock, flags);
233
234 printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
235}
236
237
238static void zf_ping(unsigned long data)
239{
240 unsigned int ctrl_reg = 0;
241 unsigned long flags;
242
243 zf_writeb(COUNTER_2, 0xff);
244
Alan Cox325ea4d2008-05-19 14:06:59 +0100245 if (time_before(jiffies, next_heartbeat)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 dprintk("time_before: %ld\n", next_heartbeat - jiffies);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 /*
248 * reset event is activated by transition from 0 to 1 on
249 * RESET_WD1 bit and we assume that it is already zero...
250 */
251
252 spin_lock_irqsave(&zf_port_lock, flags);
253 ctrl_reg = zf_get_control();
254 ctrl_reg |= RESET_WD1;
255 zf_set_control(ctrl_reg);
256
257 /* ...and nothing changes until here */
258 ctrl_reg &= ~(RESET_WD1);
259 zf_set_control(ctrl_reg);
260 spin_unlock_irqrestore(&zf_port_lock, flags);
261
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100262 mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
Alan Cox325ea4d2008-05-19 14:06:59 +0100263 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 printk(KERN_CRIT PFX ": I will reset your machine\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
267static ssize_t zf_write(struct file *file, const char __user *buf, size_t count,
268 loff_t *ppos)
269{
270 /* See if we got the magic character */
Alan Cox325ea4d2008-05-19 14:06:59 +0100271 if (count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 /*
273 * no need to check for close confirmation
274 * no way to disable watchdog ;)
275 */
276 if (!nowayout) {
277 size_t ofs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 /*
279 * note: just in case someone wrote the magic character
280 * five months ago...
281 */
282 zf_expect_close = 0;
283
284 /* now scan */
Alan Cox325ea4d2008-05-19 14:06:59 +0100285 for (ofs = 0; ofs != count; ofs++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 char c;
287 if (get_user(c, buf + ofs))
288 return -EFAULT;
Alan Cox325ea4d2008-05-19 14:06:59 +0100289 if (c == 'V') {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 zf_expect_close = 42;
291 dprintk("zf_expect_close = 42\n");
292 }
293 }
294 }
295
296 /*
297 * Well, anyhow someone wrote to us,
298 * we should return that favour
299 */
300 next_heartbeat = jiffies + ZF_USER_TIMEO;
301 dprintk("user ping at %ld\n", jiffies);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 return count;
304}
305
Alan Cox325ea4d2008-05-19 14:06:59 +0100306static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307{
308 void __user *argp = (void __user *)arg;
309 int __user *p = argp;
Andrew Mortonbad77052007-03-18 01:26:10 -0800310 switch (cmd) {
311 case WDIOC_GETSUPPORT:
312 if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
313 return -EFAULT;
314 break;
Andrew Mortonbad77052007-03-18 01:26:10 -0800315 case WDIOC_GETSTATUS:
Wim Van Sebroeck5c4eb612007-07-21 13:42:18 +0000316 case WDIOC_GETBOOTSTATUS:
Andrew Mortonbad77052007-03-18 01:26:10 -0800317 return put_user(0, p);
Andrew Mortonbad77052007-03-18 01:26:10 -0800318 case WDIOC_KEEPALIVE:
319 zf_ping(0);
320 break;
Andrew Mortonbad77052007-03-18 01:26:10 -0800321 default:
322 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 return 0;
325}
326
327static int zf_open(struct inode *inode, struct file *file)
328{
Alan Cox325ea4d2008-05-19 14:06:59 +0100329 if (test_and_set_bit(0, &zf_is_open))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 return -EBUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 if (nowayout)
332 __module_get(THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 zf_timer_on();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return nonseekable_open(inode, file);
335}
336
337static int zf_close(struct inode *inode, struct file *file)
338{
Alan Cox325ea4d2008-05-19 14:06:59 +0100339 if (zf_expect_close == 42)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 zf_timer_off();
Alan Cox325ea4d2008-05-19 14:06:59 +0100341 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 del_timer(&zf_timer);
343 printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");
344 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 clear_bit(0, &zf_is_open);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 zf_expect_close = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 return 0;
348}
349
350/*
351 * Notifier for system down
352 */
353
354static int zf_notify_sys(struct notifier_block *this, unsigned long code,
355 void *unused)
356{
Alan Cox325ea4d2008-05-19 14:06:59 +0100357 if (code == SYS_DOWN || code == SYS_HALT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 zf_timer_off();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 return NOTIFY_DONE;
360}
361
Arjan van de Ven62322d22006-07-03 00:24:21 -0700362static const struct file_operations zf_fops = {
Alan Cox325ea4d2008-05-19 14:06:59 +0100363 .owner = THIS_MODULE,
364 .llseek = no_llseek,
365 .write = zf_write,
366 .unlocked_ioctl = zf_ioctl,
367 .open = zf_open,
368 .release = zf_close,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369};
370
371static struct miscdevice zf_miscdev = {
372 .minor = WATCHDOG_MINOR,
373 .name = "watchdog",
374 .fops = &zf_fops,
375};
Alan Cox325ea4d2008-05-19 14:06:59 +0100376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
378/*
379 * The device needs to learn about soft shutdowns in order to
380 * turn the timebomb registers off.
381 */
382static struct notifier_block zf_notifier = {
383 .notifier_call = zf_notify_sys,
384};
385
386static void __init zf_show_action(int act)
387{
388 char *str[] = { "RESET", "SMI", "NMI", "SCI" };
389
390 printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
391}
392
393static int __init zf_init(void)
394{
395 int ret;
396
Alan Cox325ea4d2008-05-19 14:06:59 +0100397 printk(KERN_INFO PFX
398 ": MachZ ZF-Logic Watchdog driver initializing.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400 ret = zf_get_ZFL_version();
Alan Cox325ea4d2008-05-19 14:06:59 +0100401 if (!ret || ret == 0xffff) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 printk(KERN_WARNING PFX ": no ZF-Logic found\n");
403 return -ENODEV;
404 }
405
Alan Cox325ea4d2008-05-19 14:06:59 +0100406 if (action <= 3 && action >= 0)
407 zf_action = zf_action >> action;
408 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 action = 0;
410
411 zf_show_action(action);
412
Alan Cox325ea4d2008-05-19 14:06:59 +0100413 if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 printk(KERN_ERR "cannot reserve I/O ports at %d\n",
415 ZF_IOBASE);
416 ret = -EBUSY;
417 goto no_region;
418 }
419
420 ret = register_reboot_notifier(&zf_notifier);
Alan Cox325ea4d2008-05-19 14:06:59 +0100421 if (ret) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
423 ret);
424 goto no_reboot;
425 }
426
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300427 ret = misc_register(&zf_miscdev);
Alan Cox325ea4d2008-05-19 14:06:59 +0100428 if (ret) {
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300429 printk(KERN_ERR "can't misc_register on minor=%d\n",
430 WATCHDOG_MINOR);
431 goto no_misc;
432 }
433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 zf_set_status(0);
435 zf_set_control(0);
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return 0;
438
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300439no_misc:
440 unregister_reboot_notifier(&zf_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441no_reboot:
442 release_region(ZF_IOBASE, 3);
443no_region:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return ret;
445}
446
447
448static void __exit zf_exit(void)
449{
450 zf_timer_off();
451
452 misc_deregister(&zf_miscdev);
453 unregister_reboot_notifier(&zf_notifier);
454 release_region(ZF_IOBASE, 3);
455}
456
457module_init(zf_init);
458module_exit(zf_exit);