2 * MachZ ZF-Logic Watchdog Timer driver for Linux
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.
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.
14 * Author: Fernando Fuganti <fuganti@conectiva.com.br>
16 * Based on sbc60xxwdt.c by Jakob Oestergaard
19 * We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
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.
27 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
28 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
31 #include <linux/config.h>
32 #include <linux/module.h>
33 #include <linux/moduleparam.h>
34 #include <linux/types.h>
35 #include <linux/timer.h>
36 #include <linux/jiffies.h>
37 #include <linux/miscdevice.h>
38 #include <linux/watchdog.h>
40 #include <linux/ioport.h>
41 #include <linux/notifier.h>
42 #include <linux/reboot.h>
43 #include <linux/init.h>
46 #include <asm/uaccess.h>
47 #include <asm/system.h>
50 #define ZF_IOBASE 0x218
56 /* indexes */ /* size */
57 #define ZFL_VERSION 0x02 /* 16 */
58 #define CONTROL 0x10 /* 16 */
59 #define STATUS 0x12 /* 8 */
60 #define COUNTER_1 0x0C /* 16 */
61 #define COUNTER_2 0x0E /* 8 */
62 #define PULSE_LEN 0x0F /* 8 */
65 #define ENABLE_WD1 0x0001
66 #define ENABLE_WD2 0x0002
67 #define RESET_WD1 0x0010
68 #define RESET_WD2 0x0020
69 #define GEN_SCI 0x0100
70 #define GEN_NMI 0x0200
71 #define GEN_SMI 0x0400
72 #define GEN_RESET 0x0800
80 #define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
81 #define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
82 #define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
85 static unsigned short zf_readw(unsigned char port
)
91 static unsigned short zf_readb(unsigned char port
)
98 MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
99 MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
100 MODULE_LICENSE("GPL");
101 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);
103 #ifdef CONFIG_WATCHDOG_NOWAYOUT
104 static int nowayout
= 1;
106 static int nowayout
= 0;
109 module_param(nowayout
, int, 0);
110 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
112 #define PFX "machzwd"
114 static struct watchdog_info zf_info
= {
115 .options
= WDIOF_KEEPALIVEPING
| WDIOF_MAGICCLOSE
,
116 .firmware_version
= 1,
117 .identity
= "ZF-Logic watchdog",
122 * action refers to action taken when watchdog resets
127 * defaults to GEN_RESET (0)
129 static int action
= 0;
130 module_param(action
, int, 0);
131 MODULE_PARM_DESC(action
, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
133 static int zf_action
= GEN_RESET
;
134 static unsigned long zf_is_open
;
135 static char zf_expect_close
;
136 static spinlock_t zf_lock
;
137 static spinlock_t zf_port_lock
;
138 static struct timer_list zf_timer
;
139 static unsigned long next_heartbeat
= 0;
142 /* timeout for user land heart beat (10 seconds) */
143 #define ZF_USER_TIMEO (HZ*10)
145 /* timeout for hardware watchdog (~500ms) */
146 #define ZF_HW_TIMEO (HZ/2)
148 /* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
149 #define ZF_CTIMEOUT 0xffff
152 # define dprintk(format, args...)
154 # define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __FUNCTION__, __LINE__ , ## args)
158 /* STATUS register functions */
160 static inline unsigned char zf_get_status(void)
162 return zf_readb(STATUS
);
165 static inline void zf_set_status(unsigned char new)
167 zf_writeb(STATUS
, new);
171 /* CONTROL register functions */
173 static inline unsigned short zf_get_control(void)
175 return zf_readw(CONTROL
);
178 static inline void zf_set_control(unsigned short new)
180 zf_writew(CONTROL
, new);
184 /* WD#? counter functions */
186 * Just get current counter value
189 static inline unsigned short zf_get_timer(unsigned char n
)
193 return zf_readw(COUNTER_1
);
195 return zf_readb(COUNTER_2
);
202 * Just set counter value
205 static inline void zf_set_timer(unsigned short new, unsigned char n
)
209 zf_writew(COUNTER_1
, new);
211 zf_writeb(COUNTER_2
, new > 0xff ? 0xff : new);
218 * stop hardware timer
220 static void zf_timer_off(void)
222 unsigned int ctrl_reg
= 0;
225 /* stop internal ping */
226 del_timer_sync(&zf_timer
);
228 spin_lock_irqsave(&zf_port_lock
, flags
);
229 /* stop watchdog timer */
230 ctrl_reg
= zf_get_control();
231 ctrl_reg
|= (ENABLE_WD1
|ENABLE_WD2
); /* disable wd1 and wd2 */
232 ctrl_reg
&= ~(ENABLE_WD1
|ENABLE_WD2
);
233 zf_set_control(ctrl_reg
);
234 spin_unlock_irqrestore(&zf_port_lock
, flags
);
236 printk(KERN_INFO PFX
": Watchdog timer is now disabled\n");
241 * start hardware timer
243 static void zf_timer_on(void)
245 unsigned int ctrl_reg
= 0;
248 spin_lock_irqsave(&zf_port_lock
, flags
);
250 zf_writeb(PULSE_LEN
, 0xff);
252 zf_set_timer(ZF_CTIMEOUT
, WD1
);
255 next_heartbeat
= jiffies
+ ZF_USER_TIMEO
;
257 /* start the timer for internal ping */
258 zf_timer
.expires
= jiffies
+ ZF_HW_TIMEO
;
260 add_timer(&zf_timer
);
262 /* start watchdog timer */
263 ctrl_reg
= zf_get_control();
264 ctrl_reg
|= (ENABLE_WD1
|zf_action
);
265 zf_set_control(ctrl_reg
);
266 spin_unlock_irqrestore(&zf_port_lock
, flags
);
268 printk(KERN_INFO PFX
": Watchdog timer is now enabled\n");
272 static void zf_ping(unsigned long data
)
274 unsigned int ctrl_reg
= 0;
277 zf_writeb(COUNTER_2
, 0xff);
279 if(time_before(jiffies
, next_heartbeat
)){
281 dprintk("time_before: %ld\n", next_heartbeat
- jiffies
);
284 * reset event is activated by transition from 0 to 1 on
285 * RESET_WD1 bit and we assume that it is already zero...
288 spin_lock_irqsave(&zf_port_lock
, flags
);
289 ctrl_reg
= zf_get_control();
290 ctrl_reg
|= RESET_WD1
;
291 zf_set_control(ctrl_reg
);
293 /* ...and nothing changes until here */
294 ctrl_reg
&= ~(RESET_WD1
);
295 zf_set_control(ctrl_reg
);
296 spin_unlock_irqrestore(&zf_port_lock
, flags
);
298 zf_timer
.expires
= jiffies
+ ZF_HW_TIMEO
;
299 add_timer(&zf_timer
);
301 printk(KERN_CRIT PFX
": I will reset your machine\n");
305 static ssize_t
zf_write(struct file
*file
, const char __user
*buf
, size_t count
,
308 /* See if we got the magic character */
312 * no need to check for close confirmation
313 * no way to disable watchdog ;)
319 * note: just in case someone wrote the magic character
325 for (ofs
= 0; ofs
!= count
; ofs
++){
327 if (get_user(c
, buf
+ ofs
))
330 zf_expect_close
= 42;
331 dprintk("zf_expect_close = 42\n");
337 * Well, anyhow someone wrote to us,
338 * we should return that favour
340 next_heartbeat
= jiffies
+ ZF_USER_TIMEO
;
341 dprintk("user ping at %ld\n", jiffies
);
348 static int zf_ioctl(struct inode
*inode
, struct file
*file
, unsigned int cmd
,
351 void __user
*argp
= (void __user
*)arg
;
352 int __user
*p
= argp
;
354 case WDIOC_GETSUPPORT
:
355 if (copy_to_user(argp
, &zf_info
, sizeof(zf_info
)))
359 case WDIOC_GETSTATUS
:
360 return put_user(0, p
);
362 case WDIOC_KEEPALIVE
:
373 static int zf_open(struct inode
*inode
, struct file
*file
)
376 if(test_and_set_bit(0, &zf_is_open
)) {
377 spin_unlock(&zf_lock
);
382 __module_get(THIS_MODULE
);
384 spin_unlock(&zf_lock
);
388 return nonseekable_open(inode
, file
);
391 static int zf_close(struct inode
*inode
, struct file
*file
)
393 if(zf_expect_close
== 42){
396 del_timer(&zf_timer
);
397 printk(KERN_ERR PFX
": device file closed unexpectedly. Will not stop the WDT!\n");
401 clear_bit(0, &zf_is_open
);
402 spin_unlock(&zf_lock
);
410 * Notifier for system down
413 static int zf_notify_sys(struct notifier_block
*this, unsigned long code
,
416 if(code
== SYS_DOWN
|| code
== SYS_HALT
){
426 static struct file_operations zf_fops
= {
427 .owner
= THIS_MODULE
,
435 static struct miscdevice zf_miscdev
= {
436 .minor
= WATCHDOG_MINOR
,
443 * The device needs to learn about soft shutdowns in order to
444 * turn the timebomb registers off.
446 static struct notifier_block zf_notifier
= {
447 .notifier_call
= zf_notify_sys
,
450 static void __init
zf_show_action(int act
)
452 char *str
[] = { "RESET", "SMI", "NMI", "SCI" };
454 printk(KERN_INFO PFX
": Watchdog using action = %s\n", str
[act
]);
457 static int __init
zf_init(void)
461 printk(KERN_INFO PFX
": MachZ ZF-Logic Watchdog driver initializing.\n");
463 ret
= zf_get_ZFL_version();
464 printk("%#x\n", ret
);
465 if((!ret
) || (ret
!= 0xffff)){
466 printk(KERN_WARNING PFX
": no ZF-Logic found\n");
470 if((action
<= 3) && (action
>= 0)){
471 zf_action
= zf_action
>>action
;
475 zf_show_action(action
);
477 spin_lock_init(&zf_lock
);
478 spin_lock_init(&zf_port_lock
);
480 ret
= misc_register(&zf_miscdev
);
482 printk(KERN_ERR
"can't misc_register on minor=%d\n",
487 if(!request_region(ZF_IOBASE
, 3, "MachZ ZFL WDT")){
488 printk(KERN_ERR
"cannot reserve I/O ports at %d\n",
494 ret
= register_reboot_notifier(&zf_notifier
);
496 printk(KERN_ERR
"can't register reboot notifier (err=%d)\n",
504 /* this is the timer that will do the hard work */
505 init_timer(&zf_timer
);
506 zf_timer
.function
= zf_ping
;
512 release_region(ZF_IOBASE
, 3);
514 misc_deregister(&zf_miscdev
);
520 void __exit
zf_exit(void)
524 misc_deregister(&zf_miscdev
);
525 unregister_reboot_notifier(&zf_notifier
);
526 release_region(ZF_IOBASE
, 3);
529 module_init(zf_init
);
530 module_exit(zf_exit
);