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 #ifdef CONFIG_WATCHDOG_NOWAYOUT
33 static int nowayout = 1;
35 static int nowayout = 0;
38 #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
40 module_param(nowayout, int, 0);
41 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
43 static void indydog_start(void)
45 u32 mc_ctrl0 = sgimc->cpuctrl0;
47 mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG;
48 sgimc->cpuctrl0 = mc_ctrl0;
51 static void indydog_stop(void)
53 u32 mc_ctrl0 = sgimc->cpuctrl0;
55 mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG;
56 sgimc->cpuctrl0 = mc_ctrl0;
58 printk(KERN_INFO PFX "Stopped watchdog timer.\n");
61 static void indydog_ping(void)
67 * Allow only one person to hold it open
69 static int indydog_open(struct inode *inode, struct file *file)
75 __module_get(THIS_MODULE);
82 printk(KERN_INFO "Started watchdog timer.\n");
84 return nonseekable_open(inode, file);
87 static int indydog_release(struct inode *inode, struct file *file)
89 /* Shut off the timer.
90 * Lock it in if it's a module and we defined ...NOWAYOUT */
92 indydog_stop(); /* Turn the WDT off */
99 static ssize_t indydog_write(struct file *file, const char *data, size_t len, loff_t *ppos)
101 /* Refresh the timer. */
108 static int indydog_ioctl(struct inode *inode, struct file *file,
109 unsigned int cmd, unsigned long arg)
111 int options, retval = -EINVAL;
112 static struct watchdog_info ident = {
113 .options = WDIOF_KEEPALIVEPING |
115 .firmware_version = 0,
116 .identity = "Hardware Watchdog for SGI IP22",
122 case WDIOC_GETSUPPORT:
123 if (copy_to_user((struct watchdog_info *)arg,
124 &ident, sizeof(ident)))
127 case WDIOC_GETSTATUS:
128 case WDIOC_GETBOOTSTATUS:
129 return put_user(0,(int *)arg);
130 case WDIOC_KEEPALIVE:
133 case WDIOC_GETTIMEOUT:
134 return put_user(WATCHDOG_TIMEOUT,(int *)arg);
135 case WDIOC_SETOPTIONS:
137 if (get_user(options, (int *)arg))
140 if (options & WDIOS_DISABLECARD) {
145 if (options & WDIOS_ENABLECARD) {
155 static int indydog_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
157 if (code == SYS_DOWN || code == SYS_HALT)
158 indydog_stop(); /* Turn the WDT off */
163 static struct file_operations indydog_fops = {
164 .owner = THIS_MODULE,
166 .write = indydog_write,
167 .ioctl = indydog_ioctl,
168 .open = indydog_open,
169 .release = indydog_release,
172 static struct miscdevice indydog_miscdev = {
173 .minor = WATCHDOG_MINOR,
175 .fops = &indydog_fops,
178 static struct notifier_block indydog_notifier = {
179 .notifier_call = indydog_notify_sys,
182 static char banner[] __initdata =
183 KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n";
185 static int __init watchdog_init(void)
189 ret = register_reboot_notifier(&indydog_notifier);
191 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
196 ret = misc_register(&indydog_miscdev);
198 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
199 WATCHDOG_MINOR, ret);
200 unregister_reboot_notifier(&indydog_notifier);
209 static void __exit watchdog_exit(void)
211 misc_deregister(&indydog_miscdev);
212 unregister_reboot_notifier(&indydog_notifier);
215 module_init(watchdog_init);
216 module_exit(watchdog_exit);
218 MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
219 MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
220 MODULE_LICENSE("GPL");
221 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);