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