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Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * IndyDog 0.3 A Hardware Watchdog Device for SGI IP22 | |
4 | * | |
9b9dbcca AC |
5 | * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, |
6 | * All Rights Reserved. | |
1da177e4 | 7 | * |
29fa0586 | 8 | * based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
9 | */ |
10 | ||
27c766aa JP |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
12 | ||
1da177e4 LT |
13 | #include <linux/module.h> |
14 | #include <linux/moduleparam.h> | |
1da177e4 LT |
15 | #include <linux/types.h> |
16 | #include <linux/kernel.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/miscdevice.h> | |
20 | #include <linux/watchdog.h> | |
21 | #include <linux/notifier.h> | |
22 | #include <linux/reboot.h> | |
23 | #include <linux/init.h> | |
9b9dbcca | 24 | #include <linux/uaccess.h> |
1da177e4 LT |
25 | #include <asm/sgi/mc.h> |
26 | ||
9b9dbcca | 27 | static unsigned long indydog_alive; |
1334f329 | 28 | static DEFINE_SPINLOCK(indydog_lock); |
1da177e4 | 29 | |
1da177e4 LT |
30 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ |
31 | ||
86a1e189 WVS |
32 | static bool nowayout = WATCHDOG_NOWAYOUT; |
33 | module_param(nowayout, bool, 0); | |
9b9dbcca AC |
34 | MODULE_PARM_DESC(nowayout, |
35 | "Watchdog cannot be stopped once started (default=" | |
36 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
37 | |
38 | static void indydog_start(void) | |
39 | { | |
9b9dbcca | 40 | spin_lock(&indydog_lock); |
0c29c2e8 | 41 | sgimc->cpuctrl0 |= SGIMC_CCTRL0_WDOG; |
9b9dbcca | 42 | spin_unlock(&indydog_lock); |
1da177e4 LT |
43 | } |
44 | ||
45 | static void indydog_stop(void) | |
46 | { | |
9b9dbcca | 47 | spin_lock(&indydog_lock); |
0c29c2e8 | 48 | sgimc->cpuctrl0 &= ~SGIMC_CCTRL0_WDOG; |
9b9dbcca | 49 | spin_unlock(&indydog_lock); |
1da177e4 | 50 | |
27c766aa | 51 | pr_info("Stopped watchdog timer\n"); |
1da177e4 LT |
52 | } |
53 | ||
54 | static void indydog_ping(void) | |
55 | { | |
56 | sgimc->watchdogt = 0; | |
57 | } | |
58 | ||
59 | /* | |
60 | * Allow only one person to hold it open | |
61 | */ | |
62 | static int indydog_open(struct inode *inode, struct file *file) | |
63 | { | |
9b9dbcca | 64 | if (test_and_set_bit(0, &indydog_alive)) |
1da177e4 LT |
65 | return -EBUSY; |
66 | ||
67 | if (nowayout) | |
68 | __module_get(THIS_MODULE); | |
69 | ||
70 | /* Activate timer */ | |
71 | indydog_start(); | |
72 | indydog_ping(); | |
73 | ||
27c766aa | 74 | pr_info("Started watchdog timer\n"); |
1da177e4 | 75 | |
c5bf68fe | 76 | return stream_open(inode, file); |
1da177e4 LT |
77 | } |
78 | ||
79 | static int indydog_release(struct inode *inode, struct file *file) | |
80 | { | |
81 | /* Shut off the timer. | |
82 | * Lock it in if it's a module and we defined ...NOWAYOUT */ | |
83 | if (!nowayout) | |
84 | indydog_stop(); /* Turn the WDT off */ | |
9b9dbcca | 85 | clear_bit(0, &indydog_alive); |
1da177e4 LT |
86 | return 0; |
87 | } | |
88 | ||
9b9dbcca AC |
89 | static ssize_t indydog_write(struct file *file, const char *data, |
90 | size_t len, loff_t *ppos) | |
1da177e4 LT |
91 | { |
92 | /* Refresh the timer. */ | |
9b9dbcca | 93 | if (len) |
1da177e4 | 94 | indydog_ping(); |
1da177e4 LT |
95 | return len; |
96 | } | |
97 | ||
9b9dbcca AC |
98 | static long indydog_ioctl(struct file *file, unsigned int cmd, |
99 | unsigned long arg) | |
1da177e4 LT |
100 | { |
101 | int options, retval = -EINVAL; | |
42747d71 | 102 | static const struct watchdog_info ident = { |
e73a7802 | 103 | .options = WDIOF_KEEPALIVEPING, |
1da177e4 LT |
104 | .firmware_version = 0, |
105 | .identity = "Hardware Watchdog for SGI IP22", | |
106 | }; | |
107 | ||
108 | switch (cmd) { | |
9b9dbcca AC |
109 | case WDIOC_GETSUPPORT: |
110 | if (copy_to_user((struct watchdog_info *)arg, | |
111 | &ident, sizeof(ident))) | |
112 | return -EFAULT; | |
113 | return 0; | |
114 | case WDIOC_GETSTATUS: | |
115 | case WDIOC_GETBOOTSTATUS: | |
116 | return put_user(0, (int *)arg); | |
9b9dbcca AC |
117 | case WDIOC_SETOPTIONS: |
118 | { | |
119 | if (get_user(options, (int *)arg)) | |
120 | return -EFAULT; | |
121 | if (options & WDIOS_DISABLECARD) { | |
122 | indydog_stop(); | |
123 | retval = 0; | |
124 | } | |
125 | if (options & WDIOS_ENABLECARD) { | |
126 | indydog_start(); | |
127 | retval = 0; | |
1da177e4 | 128 | } |
9b9dbcca AC |
129 | return retval; |
130 | } | |
0c06090c WVS |
131 | case WDIOC_KEEPALIVE: |
132 | indydog_ping(); | |
133 | return 0; | |
134 | case WDIOC_GETTIMEOUT: | |
135 | return put_user(WATCHDOG_TIMEOUT, (int *)arg); | |
9b9dbcca AC |
136 | default: |
137 | return -ENOTTY; | |
1da177e4 LT |
138 | } |
139 | } | |
140 | ||
9b9dbcca AC |
141 | static int indydog_notify_sys(struct notifier_block *this, |
142 | unsigned long code, void *unused) | |
1da177e4 LT |
143 | { |
144 | if (code == SYS_DOWN || code == SYS_HALT) | |
145 | indydog_stop(); /* Turn the WDT off */ | |
146 | ||
147 | return NOTIFY_DONE; | |
148 | } | |
149 | ||
62322d25 | 150 | static const struct file_operations indydog_fops = { |
1da177e4 LT |
151 | .owner = THIS_MODULE, |
152 | .llseek = no_llseek, | |
153 | .write = indydog_write, | |
9b9dbcca | 154 | .unlocked_ioctl = indydog_ioctl, |
b6dfb247 | 155 | .compat_ioctl = compat_ptr_ioctl, |
1da177e4 LT |
156 | .open = indydog_open, |
157 | .release = indydog_release, | |
158 | }; | |
159 | ||
160 | static struct miscdevice indydog_miscdev = { | |
161 | .minor = WATCHDOG_MINOR, | |
162 | .name = "watchdog", | |
163 | .fops = &indydog_fops, | |
164 | }; | |
165 | ||
166 | static struct notifier_block indydog_notifier = { | |
167 | .notifier_call = indydog_notify_sys, | |
168 | }; | |
169 | ||
1da177e4 LT |
170 | static int __init watchdog_init(void) |
171 | { | |
172 | int ret; | |
173 | ||
174 | ret = register_reboot_notifier(&indydog_notifier); | |
175 | if (ret) { | |
27c766aa | 176 | pr_err("cannot register reboot notifier (err=%d)\n", ret); |
1da177e4 LT |
177 | return ret; |
178 | } | |
179 | ||
180 | ret = misc_register(&indydog_miscdev); | |
181 | if (ret) { | |
27c766aa JP |
182 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
183 | WATCHDOG_MINOR, ret); | |
1da177e4 LT |
184 | unregister_reboot_notifier(&indydog_notifier); |
185 | return ret; | |
186 | } | |
187 | ||
27c766aa | 188 | pr_info("Hardware Watchdog Timer for SGI IP22: 0.3\n"); |
1da177e4 LT |
189 | |
190 | return 0; | |
191 | } | |
192 | ||
193 | static void __exit watchdog_exit(void) | |
194 | { | |
195 | misc_deregister(&indydog_miscdev); | |
196 | unregister_reboot_notifier(&indydog_notifier); | |
197 | } | |
198 | ||
199 | module_init(watchdog_init); | |
200 | module_exit(watchdog_exit); | |
201 | ||
202 | MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>"); | |
203 | MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22"); | |
204 | MODULE_LICENSE("GPL"); |