Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * IndyDog 0.3 A Hardware Watchdog Device for SGI IP22 | |
3 | * | |
9b9dbcca AC |
4 | * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, |
5 | * All Rights Reserved. | |
1da177e4 LT |
6 | * |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
29fa0586 | 12 | * based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
13 | */ |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/moduleparam.h> | |
1da177e4 LT |
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> | |
9b9dbcca | 26 | #include <linux/uaccess.h> |
1da177e4 LT |
27 | #include <asm/sgi/mc.h> |
28 | ||
29 | #define PFX "indydog: " | |
9b9dbcca AC |
30 | static unsigned long indydog_alive; |
31 | static spinlock_t indydog_lock; | |
1da177e4 | 32 | |
1da177e4 LT |
33 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ |
34 | ||
4bfdf378 | 35 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 36 | module_param(nowayout, int, 0); |
9b9dbcca AC |
37 | MODULE_PARM_DESC(nowayout, |
38 | "Watchdog cannot be stopped once started (default=" | |
39 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
40 | |
41 | static void indydog_start(void) | |
42 | { | |
9b9dbcca | 43 | u32 mc_ctrl0; |
1da177e4 | 44 | |
9b9dbcca AC |
45 | spin_lock(&indydog_lock); |
46 | mc_ctrl0 = sgimc->cpuctrl0; | |
1da177e4 LT |
47 | mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG; |
48 | sgimc->cpuctrl0 = mc_ctrl0; | |
9b9dbcca | 49 | spin_unlock(&indydog_lock); |
1da177e4 LT |
50 | } |
51 | ||
52 | static void indydog_stop(void) | |
53 | { | |
9b9dbcca | 54 | u32 mc_ctrl0; |
1da177e4 | 55 | |
9b9dbcca AC |
56 | spin_lock(&indydog_lock); |
57 | ||
58 | mc_ctrl0 = sgimc->cpuctrl0; | |
1da177e4 LT |
59 | mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG; |
60 | sgimc->cpuctrl0 = mc_ctrl0; | |
9b9dbcca | 61 | spin_unlock(&indydog_lock); |
1da177e4 LT |
62 | |
63 | printk(KERN_INFO PFX "Stopped watchdog timer.\n"); | |
64 | } | |
65 | ||
66 | static void indydog_ping(void) | |
67 | { | |
68 | sgimc->watchdogt = 0; | |
69 | } | |
70 | ||
71 | /* | |
72 | * Allow only one person to hold it open | |
73 | */ | |
74 | static int indydog_open(struct inode *inode, struct file *file) | |
75 | { | |
9b9dbcca | 76 | if (test_and_set_bit(0, &indydog_alive)) |
1da177e4 LT |
77 | return -EBUSY; |
78 | ||
79 | if (nowayout) | |
80 | __module_get(THIS_MODULE); | |
81 | ||
82 | /* Activate timer */ | |
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 | ||
92 | static int indydog_release(struct inode *inode, struct file *file) | |
93 | { | |
94 | /* Shut off the timer. | |
95 | * Lock it in if it's a module and we defined ...NOWAYOUT */ | |
96 | if (!nowayout) | |
97 | indydog_stop(); /* Turn the WDT off */ | |
9b9dbcca | 98 | clear_bit(0, &indydog_alive); |
1da177e4 LT |
99 | return 0; |
100 | } | |
101 | ||
9b9dbcca AC |
102 | static ssize_t indydog_write(struct file *file, const char *data, |
103 | size_t len, loff_t *ppos) | |
1da177e4 LT |
104 | { |
105 | /* Refresh the timer. */ | |
9b9dbcca | 106 | if (len) |
1da177e4 | 107 | indydog_ping(); |
1da177e4 LT |
108 | return len; |
109 | } | |
110 | ||
9b9dbcca AC |
111 | static long indydog_ioctl(struct file *file, unsigned int cmd, |
112 | unsigned long arg) | |
1da177e4 LT |
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) { | |
9b9dbcca AC |
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); | |
9b9dbcca AC |
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; | |
1da177e4 | 142 | } |
9b9dbcca AC |
143 | return retval; |
144 | } | |
0c06090c WVS |
145 | case WDIOC_KEEPALIVE: |
146 | indydog_ping(); | |
147 | return 0; | |
148 | case WDIOC_GETTIMEOUT: | |
149 | return put_user(WATCHDOG_TIMEOUT, (int *)arg); | |
9b9dbcca AC |
150 | default: |
151 | return -ENOTTY; | |
1da177e4 LT |
152 | } |
153 | } | |
154 | ||
9b9dbcca AC |
155 | static int indydog_notify_sys(struct notifier_block *this, |
156 | unsigned long code, void *unused) | |
1da177e4 LT |
157 | { |
158 | if (code == SYS_DOWN || code == SYS_HALT) | |
159 | indydog_stop(); /* Turn the WDT off */ | |
160 | ||
161 | return NOTIFY_DONE; | |
162 | } | |
163 | ||
62322d25 | 164 | static const struct file_operations indydog_fops = { |
1da177e4 LT |
165 | .owner = THIS_MODULE, |
166 | .llseek = no_llseek, | |
167 | .write = indydog_write, | |
9b9dbcca | 168 | .unlocked_ioctl = indydog_ioctl, |
1da177e4 LT |
169 | .open = indydog_open, |
170 | .release = indydog_release, | |
171 | }; | |
172 | ||
173 | static struct miscdevice indydog_miscdev = { | |
174 | .minor = WATCHDOG_MINOR, | |
175 | .name = "watchdog", | |
176 | .fops = &indydog_fops, | |
177 | }; | |
178 | ||
179 | static struct notifier_block indydog_notifier = { | |
180 | .notifier_call = indydog_notify_sys, | |
181 | }; | |
182 | ||
183 | static char banner[] __initdata = | |
184 | KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n"; | |
185 | ||
186 | static int __init watchdog_init(void) | |
187 | { | |
188 | int ret; | |
189 | ||
9b9dbcca AC |
190 | spin_lock_init(&indydog_lock); |
191 | ||
1da177e4 LT |
192 | ret = register_reboot_notifier(&indydog_notifier); |
193 | if (ret) { | |
9b9dbcca AC |
194 | printk(KERN_ERR PFX |
195 | "cannot register reboot notifier (err=%d)\n", ret); | |
1da177e4 LT |
196 | return ret; |
197 | } | |
198 | ||
199 | ret = misc_register(&indydog_miscdev); | |
200 | if (ret) { | |
9b9dbcca AC |
201 | printk(KERN_ERR PFX |
202 | "cannot register miscdev on minor=%d (err=%d)\n", | |
203 | WATCHDOG_MINOR, ret); | |
1da177e4 LT |
204 | unregister_reboot_notifier(&indydog_notifier); |
205 | return ret; | |
206 | } | |
207 | ||
208 | printk(banner); | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
213 | static void __exit watchdog_exit(void) | |
214 | { | |
215 | misc_deregister(&indydog_miscdev); | |
216 | unregister_reboot_notifier(&indydog_notifier); | |
217 | } | |
218 | ||
219 | module_init(watchdog_init); | |
220 | module_exit(watchdog_exit); | |
221 | ||
222 | MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>"); | |
223 | MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22"); | |
224 | MODULE_LICENSE("GPL"); | |
225 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |