1
2
3
4
5
6
7
8
9
10
11
12
13
14
15#include <linux/module.h>
16#include <linux/moduleparam.h>
17#include <linux/types.h>
18#include <linux/kernel.h>
19#include <linux/fs.h>
20#include <linux/mm.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 <linux/uaccess.h>
27#include <asm/sgi/mc.h>
28
29#define PFX "indydog: "
30static unsigned long indydog_alive;
31static spinlock_t indydog_lock;
32
33#define WATCHDOG_TIMEOUT 30
34
35static int nowayout = WATCHDOG_NOWAYOUT;
36module_param(nowayout, int, 0);
37MODULE_PARM_DESC(nowayout,
38 "Watchdog cannot be stopped once started (default="
39 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
40
41static void indydog_start(void)
42{
43 u32 mc_ctrl0;
44
45 spin_lock(&indydog_lock);
46 mc_ctrl0 = sgimc->cpuctrl0;
47 mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG;
48 sgimc->cpuctrl0 = mc_ctrl0;
49 spin_unlock(&indydog_lock);
50}
51
52static void indydog_stop(void)
53{
54 u32 mc_ctrl0;
55
56 spin_lock(&indydog_lock);
57
58 mc_ctrl0 = sgimc->cpuctrl0;
59 mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG;
60 sgimc->cpuctrl0 = mc_ctrl0;
61 spin_unlock(&indydog_lock);
62
63 printk(KERN_INFO PFX "Stopped watchdog timer.\n");
64}
65
66static void indydog_ping(void)
67{
68 sgimc->watchdogt = 0;
69}
70
71
72
73
74static int indydog_open(struct inode *inode, struct file *file)
75{
76 if (test_and_set_bit(0, &indydog_alive))
77 return -EBUSY;
78
79 if (nowayout)
80 __module_get(THIS_MODULE);
81
82
83 indydog_start();
84 indydog_ping();
85
86 indydog_alive = 1;
87 printk(KERN_INFO "Started watchdog timer.\n");
88
89 return nonseekable_open(inode, file);
90}
91
92static int indydog_release(struct inode *inode, struct file *file)
93{
94
95
96 if (!nowayout)
97 indydog_stop();
98 clear_bit(0, &indydog_alive);
99 return 0;
100}
101
102static ssize_t indydog_write(struct file *file, const char *data,
103 size_t len, loff_t *ppos)
104{
105
106 if (len)
107 indydog_ping();
108 return len;
109}
110
111static long indydog_ioctl(struct file *file, unsigned int cmd,
112 unsigned long arg)
113{
114 int options, retval = -EINVAL;
115 static struct watchdog_info ident = {
116 .options = WDIOF_KEEPALIVEPING |
117 WDIOF_MAGICCLOSE,
118 .firmware_version = 0,
119 .identity = "Hardware Watchdog for SGI IP22",
120 };
121
122 switch (cmd) {
123 case WDIOC_GETSUPPORT:
124 if (copy_to_user((struct watchdog_info *)arg,
125 &ident, sizeof(ident)))
126 return -EFAULT;
127 return 0;
128 case WDIOC_GETSTATUS:
129 case WDIOC_GETBOOTSTATUS:
130 return put_user(0, (int *)arg);
131 case WDIOC_SETOPTIONS:
132 {
133 if (get_user(options, (int *)arg))
134 return -EFAULT;
135 if (options & WDIOS_DISABLECARD) {
136 indydog_stop();
137 retval = 0;
138 }
139 if (options & WDIOS_ENABLECARD) {
140 indydog_start();
141 retval = 0;
142 }
143 return retval;
144 }
145 case WDIOC_KEEPALIVE:
146 indydog_ping();
147 return 0;
148 case WDIOC_GETTIMEOUT:
149 return put_user(WATCHDOG_TIMEOUT, (int *)arg);
150 default:
151 return -ENOTTY;
152 }
153}
154
155static int indydog_notify_sys(struct notifier_block *this,
156 unsigned long code, void *unused)
157{
158 if (code == SYS_DOWN || code == SYS_HALT)
159 indydog_stop();
160
161 return NOTIFY_DONE;
162}
163
164static const struct file_operations indydog_fops = {
165 .owner = THIS_MODULE,
166 .llseek = no_llseek,
167 .write = indydog_write,
168 .unlocked_ioctl = indydog_ioctl,
169 .open = indydog_open,
170 .release = indydog_release,
171};
172
173static struct miscdevice indydog_miscdev = {
174 .minor = WATCHDOG_MINOR,
175 .name = "watchdog",
176 .fops = &indydog_fops,
177};
178
179static struct notifier_block indydog_notifier = {
180 .notifier_call = indydog_notify_sys,
181};
182
183static char banner[] __initdata =
184 KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n";
185
186static int __init watchdog_init(void)
187{
188 int ret;
189
190 spin_lock_init(&indydog_lock);
191
192 ret = register_reboot_notifier(&indydog_notifier);
193 if (ret) {
194 printk(KERN_ERR PFX
195 "cannot register reboot notifier (err=%d)\n", ret);
196 return ret;
197 }
198
199 ret = misc_register(&indydog_miscdev);
200 if (ret) {
201 printk(KERN_ERR PFX
202 "cannot register miscdev on minor=%d (err=%d)\n",
203 WATCHDOG_MINOR, ret);
204 unregister_reboot_notifier(&indydog_notifier);
205 return ret;
206 }
207
208 printk(banner);
209
210 return 0;
211}
212
213static void __exit watchdog_exit(void)
214{
215 misc_deregister(&indydog_miscdev);
216 unregister_reboot_notifier(&indydog_notifier);
217}
218
219module_init(watchdog_init);
220module_exit(watchdog_exit);
221
222MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
223MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
224MODULE_LICENSE("GPL");
225MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
226
