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 | ||
27c766aa JP |
15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
16 | ||
1da177e4 LT |
17 | #include <linux/module.h> |
18 | #include <linux/moduleparam.h> | |
1da177e4 LT |
19 | #include <linux/types.h> |
20 | #include <linux/kernel.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/miscdevice.h> | |
24 | #include <linux/watchdog.h> | |
25 | #include <linux/notifier.h> | |
26 | #include <linux/reboot.h> | |
27 | #include <linux/init.h> | |
9b9dbcca | 28 | #include <linux/uaccess.h> |
1da177e4 LT |
29 | #include <asm/sgi/mc.h> |
30 | ||
9b9dbcca | 31 | static unsigned long indydog_alive; |
1334f329 | 32 | static DEFINE_SPINLOCK(indydog_lock); |
1da177e4 | 33 | |
1da177e4 LT |
34 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ |
35 | ||
86a1e189 WVS |
36 | static bool nowayout = WATCHDOG_NOWAYOUT; |
37 | module_param(nowayout, bool, 0); | |
9b9dbcca AC |
38 | MODULE_PARM_DESC(nowayout, |
39 | "Watchdog cannot be stopped once started (default=" | |
40 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
41 | |
42 | static void indydog_start(void) | |
43 | { | |
9b9dbcca | 44 | u32 mc_ctrl0; |
1da177e4 | 45 | |
9b9dbcca AC |
46 | spin_lock(&indydog_lock); |
47 | mc_ctrl0 = sgimc->cpuctrl0; | |
1da177e4 LT |
48 | mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG; |
49 | sgimc->cpuctrl0 = mc_ctrl0; | |
9b9dbcca | 50 | spin_unlock(&indydog_lock); |
1da177e4 LT |
51 | } |
52 | ||
53 | static void indydog_stop(void) | |
54 | { | |
9b9dbcca | 55 | u32 mc_ctrl0; |
1da177e4 | 56 | |
9b9dbcca AC |
57 | spin_lock(&indydog_lock); |
58 | ||
59 | mc_ctrl0 = sgimc->cpuctrl0; | |
1da177e4 LT |
60 | mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG; |
61 | sgimc->cpuctrl0 = mc_ctrl0; | |
9b9dbcca | 62 | spin_unlock(&indydog_lock); |
1da177e4 | 63 | |
27c766aa | 64 | pr_info("Stopped watchdog timer\n"); |
1da177e4 LT |
65 | } |
66 | ||
67 | static void indydog_ping(void) | |
68 | { | |
69 | sgimc->watchdogt = 0; | |
70 | } | |
71 | ||
72 | /* | |
73 | * Allow only one person to hold it open | |
74 | */ | |
75 | static int indydog_open(struct inode *inode, struct file *file) | |
76 | { | |
9b9dbcca | 77 | if (test_and_set_bit(0, &indydog_alive)) |
1da177e4 LT |
78 | return -EBUSY; |
79 | ||
80 | if (nowayout) | |
81 | __module_get(THIS_MODULE); | |
82 | ||
83 | /* Activate timer */ | |
84 | indydog_start(); | |
85 | indydog_ping(); | |
86 | ||
27c766aa | 87 | pr_info("Started watchdog timer\n"); |
1da177e4 LT |
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; | |
42747d71 | 115 | static const struct watchdog_info ident = { |
e73a7802 | 116 | .options = WDIOF_KEEPALIVEPING, |
1da177e4 LT |
117 | .firmware_version = 0, |
118 | .identity = "Hardware Watchdog for SGI IP22", | |
119 | }; | |
120 | ||
121 | switch (cmd) { | |
9b9dbcca AC |
122 | case WDIOC_GETSUPPORT: |
123 | if (copy_to_user((struct watchdog_info *)arg, | |
124 | &ident, sizeof(ident))) | |
125 | return -EFAULT; | |
126 | return 0; | |
127 | case WDIOC_GETSTATUS: | |
128 | case WDIOC_GETBOOTSTATUS: | |
129 | return put_user(0, (int *)arg); | |
9b9dbcca AC |
130 | case WDIOC_SETOPTIONS: |
131 | { | |
132 | if (get_user(options, (int *)arg)) | |
133 | return -EFAULT; | |
134 | if (options & WDIOS_DISABLECARD) { | |
135 | indydog_stop(); | |
136 | retval = 0; | |
137 | } | |
138 | if (options & WDIOS_ENABLECARD) { | |
139 | indydog_start(); | |
140 | retval = 0; | |
1da177e4 | 141 | } |
9b9dbcca AC |
142 | return retval; |
143 | } | |
0c06090c WVS |
144 | case WDIOC_KEEPALIVE: |
145 | indydog_ping(); | |
146 | return 0; | |
147 | case WDIOC_GETTIMEOUT: | |
148 | return put_user(WATCHDOG_TIMEOUT, (int *)arg); | |
9b9dbcca AC |
149 | default: |
150 | return -ENOTTY; | |
1da177e4 LT |
151 | } |
152 | } | |
153 | ||
9b9dbcca AC |
154 | static int indydog_notify_sys(struct notifier_block *this, |
155 | unsigned long code, void *unused) | |
1da177e4 LT |
156 | { |
157 | if (code == SYS_DOWN || code == SYS_HALT) | |
158 | indydog_stop(); /* Turn the WDT off */ | |
159 | ||
160 | return NOTIFY_DONE; | |
161 | } | |
162 | ||
62322d25 | 163 | static const struct file_operations indydog_fops = { |
1da177e4 LT |
164 | .owner = THIS_MODULE, |
165 | .llseek = no_llseek, | |
166 | .write = indydog_write, | |
9b9dbcca | 167 | .unlocked_ioctl = indydog_ioctl, |
1da177e4 LT |
168 | .open = indydog_open, |
169 | .release = indydog_release, | |
170 | }; | |
171 | ||
172 | static struct miscdevice indydog_miscdev = { | |
173 | .minor = WATCHDOG_MINOR, | |
174 | .name = "watchdog", | |
175 | .fops = &indydog_fops, | |
176 | }; | |
177 | ||
178 | static struct notifier_block indydog_notifier = { | |
179 | .notifier_call = indydog_notify_sys, | |
180 | }; | |
181 | ||
1da177e4 LT |
182 | static int __init watchdog_init(void) |
183 | { | |
184 | int ret; | |
185 | ||
186 | ret = register_reboot_notifier(&indydog_notifier); | |
187 | if (ret) { | |
27c766aa | 188 | pr_err("cannot register reboot notifier (err=%d)\n", ret); |
1da177e4 LT |
189 | return ret; |
190 | } | |
191 | ||
192 | ret = misc_register(&indydog_miscdev); | |
193 | if (ret) { | |
27c766aa JP |
194 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
195 | WATCHDOG_MINOR, ret); | |
1da177e4 LT |
196 | unregister_reboot_notifier(&indydog_notifier); |
197 | return ret; | |
198 | } | |
199 | ||
27c766aa | 200 | pr_info("Hardware Watchdog Timer for SGI IP22: 0.3\n"); |
1da177e4 LT |
201 | |
202 | return 0; | |
203 | } | |
204 | ||
205 | static void __exit watchdog_exit(void) | |
206 | { | |
207 | misc_deregister(&indydog_miscdev); | |
208 | unregister_reboot_notifier(&indydog_notifier); | |
209 | } | |
210 | ||
211 | module_init(watchdog_init); | |
212 | module_exit(watchdog_exit); | |
213 | ||
214 | MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>"); | |
215 | MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22"); | |
216 | MODULE_LICENSE("GPL"); | |
217 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |