2 * Intel 21285 watchdog driver
3 * Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
7 * SoftDog 0.05: A Software Watchdog Device
9 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
10 * All Rights Reserved.
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
25 #include <linux/miscdevice.h>
26 #include <linux/watchdog.h>
27 #include <linux/reboot.h>
28 #include <linux/init.h>
29 #include <linux/interrupt.h>
30 #include <linux/uaccess.h>
31 #include <linux/irq.h>
32 #include <mach/hardware.h>
34 #include <asm/mach-types.h>
35 #include <asm/system_info.h>
36 #include <asm/hardware/dec21285.h>
39 * Define this to stop the watchdog actually rebooting the machine.
43 static unsigned int soft_margin
= 60; /* in seconds */
44 static unsigned int reload
;
45 static unsigned long timer_alive
;
49 * If the timer expires..
51 static void watchdog_fire(int irq
, void *dev_id
)
53 printk(KERN_CRIT
"Watchdog: Would Reboot.\n");
62 static void watchdog_ping(void)
64 *CSR_TIMER4_LOAD
= reload
;
68 * Allow only one person to hold it open
70 static int watchdog_open(struct inode
*inode
, struct file
*file
)
74 if (*CSR_SA110_CNTL
& (1 << 13))
77 if (test_and_set_bit(1, &timer_alive
))
80 reload
= soft_margin
* (mem_fclk_21285
/ 256);
84 *CSR_TIMER4_CNTL
= TIMER_CNTL_ENABLE
| TIMER_CNTL_AUTORELOAD
88 ret
= request_irq(IRQ_TIMER4
, watchdog_fire
, 0, "watchdog", NULL
);
91 clear_bit(1, &timer_alive
);
95 * Setting this bit is irreversible; once enabled, there is
96 * no way to disable the watchdog.
98 *CSR_SA110_CNTL
|= 1 << 13;
102 nonseekable_open(inode
, file
);
107 * Shut off the timer.
108 * Note: if we really have enabled the watchdog, there
109 * is no way to turn off.
111 static int watchdog_release(struct inode
*inode
, struct file
*file
)
114 free_irq(IRQ_TIMER4
, NULL
);
115 clear_bit(1, &timer_alive
);
120 static ssize_t
watchdog_write(struct file
*file
, const char __user
*data
,
121 size_t len
, loff_t
*ppos
)
132 static const struct watchdog_info ident
= {
133 .options
= WDIOF_SETTIMEOUT
,
134 .identity
= "Footbridge Watchdog",
137 static long watchdog_ioctl(struct file
*file
, unsigned int cmd
,
140 unsigned int new_margin
;
141 int __user
*int_arg
= (int __user
*)arg
;
145 case WDIOC_GETSUPPORT
:
147 if (copy_to_user((void __user
*)arg
, &ident
, sizeof(ident
)))
151 case WDIOC_GETSTATUS
:
152 case WDIOC_GETBOOTSTATUS
:
153 ret
= put_user(0, int_arg
);
156 case WDIOC_KEEPALIVE
:
161 case WDIOC_SETTIMEOUT
:
162 ret
= get_user(new_margin
, int_arg
);
166 /* Arbitrary, can't find the card's limits */
167 if (new_margin
< 0 || new_margin
> 60) {
172 soft_margin
= new_margin
;
173 reload
= soft_margin
* (mem_fclk_21285
/ 256);
176 case WDIOC_GETTIMEOUT
:
177 ret
= put_user(soft_margin
, int_arg
);
183 static const struct file_operations watchdog_fops
= {
184 .owner
= THIS_MODULE
,
186 .write
= watchdog_write
,
187 .unlocked_ioctl
= watchdog_ioctl
,
188 .open
= watchdog_open
,
189 .release
= watchdog_release
,
192 static struct miscdevice watchdog_miscdev
= {
193 .minor
= WATCHDOG_MINOR
,
195 .fops
= &watchdog_fops
,
198 static int __init
footbridge_watchdog_init(void)
202 if (machine_is_netwinder())
205 retval
= misc_register(&watchdog_miscdev
);
210 "Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n",
213 if (machine_is_cats())
215 "Warning: Watchdog reset may not work on this machine.\n");
219 static void __exit
footbridge_watchdog_exit(void)
221 misc_deregister(&watchdog_miscdev
);
224 MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
225 MODULE_DESCRIPTION("Footbridge watchdog driver");
226 MODULE_LICENSE("GPL");
227 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);
229 module_param(soft_margin
, int, 0);
230 MODULE_PARM_DESC(soft_margin
, "Watchdog timeout in seconds");
232 module_init(footbridge_watchdog_init
);
233 module_exit(footbridge_watchdog_exit
);