2 * IndyDog 0.3 A Hardware Watchdog Device for SGI IP22
4 * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 * based on softdog.c by Alan Cox <alan@redhat.com>
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/config.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
21 #include <linux/miscdevice.h>
22 #include <linux/watchdog.h>
23 #include <linux/notifier.h>
24 #include <linux/reboot.h>
25 #include <linux/init.h>
26 #include <asm/uaccess.h>
27 #include <asm/sgi/mc.h>
29 #define PFX "indydog: "
30 static int indydog_alive
;
32 #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
34 static int nowayout
= WATCHDOG_NOWAYOUT
;
35 module_param(nowayout
, int, 0);
36 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
38 static void indydog_start(void)
40 u32 mc_ctrl0
= sgimc
->cpuctrl0
;
42 mc_ctrl0
= sgimc
->cpuctrl0
| SGIMC_CCTRL0_WDOG
;
43 sgimc
->cpuctrl0
= mc_ctrl0
;
46 static void indydog_stop(void)
48 u32 mc_ctrl0
= sgimc
->cpuctrl0
;
50 mc_ctrl0
&= ~SGIMC_CCTRL0_WDOG
;
51 sgimc
->cpuctrl0
= mc_ctrl0
;
53 printk(KERN_INFO PFX
"Stopped watchdog timer.\n");
56 static void indydog_ping(void)
62 * Allow only one person to hold it open
64 static int indydog_open(struct inode
*inode
, struct file
*file
)
70 __module_get(THIS_MODULE
);
77 printk(KERN_INFO
"Started watchdog timer.\n");
79 return nonseekable_open(inode
, file
);
82 static int indydog_release(struct inode
*inode
, struct file
*file
)
84 /* Shut off the timer.
85 * Lock it in if it's a module and we defined ...NOWAYOUT */
87 indydog_stop(); /* Turn the WDT off */
94 static ssize_t
indydog_write(struct file
*file
, const char *data
, size_t len
, loff_t
*ppos
)
96 /* Refresh the timer. */
103 static int indydog_ioctl(struct inode
*inode
, struct file
*file
,
104 unsigned int cmd
, unsigned long arg
)
106 int options
, retval
= -EINVAL
;
107 static struct watchdog_info ident
= {
108 .options
= WDIOF_KEEPALIVEPING
|
110 .firmware_version
= 0,
111 .identity
= "Hardware Watchdog for SGI IP22",
117 case WDIOC_GETSUPPORT
:
118 if (copy_to_user((struct watchdog_info
*)arg
,
119 &ident
, sizeof(ident
)))
122 case WDIOC_GETSTATUS
:
123 case WDIOC_GETBOOTSTATUS
:
124 return put_user(0,(int *)arg
);
125 case WDIOC_KEEPALIVE
:
128 case WDIOC_GETTIMEOUT
:
129 return put_user(WATCHDOG_TIMEOUT
,(int *)arg
);
130 case WDIOC_SETOPTIONS
:
132 if (get_user(options
, (int *)arg
))
135 if (options
& WDIOS_DISABLECARD
) {
140 if (options
& WDIOS_ENABLECARD
) {
150 static int indydog_notify_sys(struct notifier_block
*this, unsigned long code
, void *unused
)
152 if (code
== SYS_DOWN
|| code
== SYS_HALT
)
153 indydog_stop(); /* Turn the WDT off */
158 static struct file_operations indydog_fops
= {
159 .owner
= THIS_MODULE
,
161 .write
= indydog_write
,
162 .ioctl
= indydog_ioctl
,
163 .open
= indydog_open
,
164 .release
= indydog_release
,
167 static struct miscdevice indydog_miscdev
= {
168 .minor
= WATCHDOG_MINOR
,
170 .fops
= &indydog_fops
,
173 static struct notifier_block indydog_notifier
= {
174 .notifier_call
= indydog_notify_sys
,
177 static char banner
[] __initdata
=
178 KERN_INFO PFX
"Hardware Watchdog Timer for SGI IP22: 0.3\n";
180 static int __init
watchdog_init(void)
184 ret
= register_reboot_notifier(&indydog_notifier
);
186 printk(KERN_ERR PFX
"cannot register reboot notifier (err=%d)\n",
191 ret
= misc_register(&indydog_miscdev
);
193 printk(KERN_ERR PFX
"cannot register miscdev on minor=%d (err=%d)\n",
194 WATCHDOG_MINOR
, ret
);
195 unregister_reboot_notifier(&indydog_notifier
);
204 static void __exit
watchdog_exit(void)
206 misc_deregister(&indydog_miscdev
);
207 unregister_reboot_notifier(&indydog_notifier
);
210 module_init(watchdog_init
);
211 module_exit(watchdog_exit
);
213 MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
214 MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
215 MODULE_LICENSE("GPL");
216 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);