diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/scx200_wdt.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/watchdog/scx200_wdt.c')
-rw-r--r-- | drivers/char/watchdog/scx200_wdt.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/char/watchdog/scx200_wdt.c b/drivers/char/watchdog/scx200_wdt.c new file mode 100644 index 000000000000..b569670e4ed5 --- /dev/null +++ b/drivers/char/watchdog/scx200_wdt.c | |||
@@ -0,0 +1,274 @@ | |||
1 | /* drivers/char/watchdog/scx200_wdt.c | ||
2 | |||
3 | National Semiconductor SCx200 Watchdog support | ||
4 | |||
5 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> | ||
6 | |||
7 | Some code taken from: | ||
8 | National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver | ||
9 | (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com> | ||
10 | |||
11 | This program is free software; you can redistribute it and/or | ||
12 | modify it under the terms of the GNU General Public License as | ||
13 | published by the Free Software Foundation; either version 2 of the | ||
14 | License, or (at your option) any later version. | ||
15 | |||
16 | The author(s) of this software shall not be held liable for damages | ||
17 | of any nature resulting due to the use of this software. This | ||
18 | software is provided AS-IS with no warranties. */ | ||
19 | |||
20 | #include <linux/config.h> | ||
21 | #include <linux/module.h> | ||
22 | #include <linux/moduleparam.h> | ||
23 | #include <linux/init.h> | ||
24 | #include <linux/miscdevice.h> | ||
25 | #include <linux/watchdog.h> | ||
26 | #include <linux/notifier.h> | ||
27 | #include <linux/reboot.h> | ||
28 | #include <linux/fs.h> | ||
29 | #include <linux/pci.h> | ||
30 | #include <linux/scx200.h> | ||
31 | |||
32 | #include <asm/uaccess.h> | ||
33 | #include <asm/io.h> | ||
34 | |||
35 | #define NAME "scx200_wdt" | ||
36 | |||
37 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); | ||
38 | MODULE_DESCRIPTION("NatSemi SCx200 Watchdog Driver"); | ||
39 | MODULE_LICENSE("GPL"); | ||
40 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
41 | |||
42 | #ifndef CONFIG_WATCHDOG_NOWAYOUT | ||
43 | #define CONFIG_WATCHDOG_NOWAYOUT 0 | ||
44 | #endif | ||
45 | |||
46 | static int margin = 60; /* in seconds */ | ||
47 | module_param(margin, int, 0); | ||
48 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds"); | ||
49 | |||
50 | static int nowayout = CONFIG_WATCHDOG_NOWAYOUT; | ||
51 | module_param(nowayout, int, 0); | ||
52 | MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); | ||
53 | |||
54 | static u16 wdto_restart; | ||
55 | static struct semaphore open_semaphore; | ||
56 | static char expect_close; | ||
57 | |||
58 | /* Bits of the WDCNFG register */ | ||
59 | #define W_ENABLE 0x00fa /* Enable watchdog */ | ||
60 | #define W_DISABLE 0x0000 /* Disable watchdog */ | ||
61 | |||
62 | /* The scaling factor for the timer, this depends on the value of W_ENABLE */ | ||
63 | #define W_SCALE (32768/1024) | ||
64 | |||
65 | static void scx200_wdt_ping(void) | ||
66 | { | ||
67 | outw(wdto_restart, scx200_cb_base + SCx200_WDT_WDTO); | ||
68 | } | ||
69 | |||
70 | static void scx200_wdt_update_margin(void) | ||
71 | { | ||
72 | printk(KERN_INFO NAME ": timer margin %d seconds\n", margin); | ||
73 | wdto_restart = margin * W_SCALE; | ||
74 | } | ||
75 | |||
76 | static void scx200_wdt_enable(void) | ||
77 | { | ||
78 | printk(KERN_DEBUG NAME ": enabling watchdog timer, wdto_restart = %d\n", | ||
79 | wdto_restart); | ||
80 | |||
81 | outw(0, scx200_cb_base + SCx200_WDT_WDTO); | ||
82 | outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS); | ||
83 | outw(W_ENABLE, scx200_cb_base + SCx200_WDT_WDCNFG); | ||
84 | |||
85 | scx200_wdt_ping(); | ||
86 | } | ||
87 | |||
88 | static void scx200_wdt_disable(void) | ||
89 | { | ||
90 | printk(KERN_DEBUG NAME ": disabling watchdog timer\n"); | ||
91 | |||
92 | outw(0, scx200_cb_base + SCx200_WDT_WDTO); | ||
93 | outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS); | ||
94 | outw(W_DISABLE, scx200_cb_base + SCx200_WDT_WDCNFG); | ||
95 | } | ||
96 | |||
97 | static int scx200_wdt_open(struct inode *inode, struct file *file) | ||
98 | { | ||
99 | /* only allow one at a time */ | ||
100 | if (down_trylock(&open_semaphore)) | ||
101 | return -EBUSY; | ||
102 | scx200_wdt_enable(); | ||
103 | |||
104 | return nonseekable_open(inode, file); | ||
105 | } | ||
106 | |||
107 | static int scx200_wdt_release(struct inode *inode, struct file *file) | ||
108 | { | ||
109 | if (expect_close != 42) { | ||
110 | printk(KERN_WARNING NAME ": watchdog device closed unexpectedly, will not disable the watchdog timer\n"); | ||
111 | } else if (!nowayout) { | ||
112 | scx200_wdt_disable(); | ||
113 | } | ||
114 | expect_close = 0; | ||
115 | up(&open_semaphore); | ||
116 | |||
117 | return 0; | ||
118 | } | ||
119 | |||
120 | static int scx200_wdt_notify_sys(struct notifier_block *this, | ||
121 | unsigned long code, void *unused) | ||
122 | { | ||
123 | if (code == SYS_HALT || code == SYS_POWER_OFF) | ||
124 | if (!nowayout) | ||
125 | scx200_wdt_disable(); | ||
126 | |||
127 | return NOTIFY_DONE; | ||
128 | } | ||
129 | |||
130 | static struct notifier_block scx200_wdt_notifier = | ||
131 | { | ||
132 | .notifier_call = scx200_wdt_notify_sys, | ||
133 | }; | ||
134 | |||
135 | static ssize_t scx200_wdt_write(struct file *file, const char __user *data, | ||
136 | size_t len, loff_t *ppos) | ||
137 | { | ||
138 | /* check for a magic close character */ | ||
139 | if (len) | ||
140 | { | ||
141 | size_t i; | ||
142 | |||
143 | scx200_wdt_ping(); | ||
144 | |||
145 | expect_close = 0; | ||
146 | for (i = 0; i < len; ++i) { | ||
147 | char c; | ||
148 | if (get_user(c, data+i)) | ||
149 | return -EFAULT; | ||
150 | if (c == 'V') | ||
151 | expect_close = 42; | ||
152 | } | ||
153 | |||
154 | return len; | ||
155 | } | ||
156 | |||
157 | return 0; | ||
158 | } | ||
159 | |||
160 | static int scx200_wdt_ioctl(struct inode *inode, struct file *file, | ||
161 | unsigned int cmd, unsigned long arg) | ||
162 | { | ||
163 | void __user *argp = (void __user *)arg; | ||
164 | int __user *p = argp; | ||
165 | static struct watchdog_info ident = { | ||
166 | .identity = "NatSemi SCx200 Watchdog", | ||
167 | .firmware_version = 1, | ||
168 | .options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING), | ||
169 | }; | ||
170 | int new_margin; | ||
171 | |||
172 | switch (cmd) { | ||
173 | default: | ||
174 | return -ENOIOCTLCMD; | ||
175 | case WDIOC_GETSUPPORT: | ||
176 | if(copy_to_user(argp, &ident, sizeof(ident))) | ||
177 | return -EFAULT; | ||
178 | return 0; | ||
179 | case WDIOC_GETSTATUS: | ||
180 | case WDIOC_GETBOOTSTATUS: | ||
181 | if (put_user(0, p)) | ||
182 | return -EFAULT; | ||
183 | return 0; | ||
184 | case WDIOC_KEEPALIVE: | ||
185 | scx200_wdt_ping(); | ||
186 | return 0; | ||
187 | case WDIOC_SETTIMEOUT: | ||
188 | if (get_user(new_margin, p)) | ||
189 | return -EFAULT; | ||
190 | if (new_margin < 1) | ||
191 | return -EINVAL; | ||
192 | margin = new_margin; | ||
193 | scx200_wdt_update_margin(); | ||
194 | scx200_wdt_ping(); | ||
195 | case WDIOC_GETTIMEOUT: | ||
196 | if (put_user(margin, p)) | ||
197 | return -EFAULT; | ||
198 | return 0; | ||
199 | } | ||
200 | } | ||
201 | |||
202 | static struct file_operations scx200_wdt_fops = { | ||
203 | .owner = THIS_MODULE, | ||
204 | .llseek = no_llseek, | ||
205 | .write = scx200_wdt_write, | ||
206 | .ioctl = scx200_wdt_ioctl, | ||
207 | .open = scx200_wdt_open, | ||
208 | .release = scx200_wdt_release, | ||
209 | }; | ||
210 | |||
211 | static struct miscdevice scx200_wdt_miscdev = { | ||
212 | .minor = WATCHDOG_MINOR, | ||
213 | .name = NAME, | ||
214 | .fops = &scx200_wdt_fops, | ||
215 | }; | ||
216 | |||
217 | static int __init scx200_wdt_init(void) | ||
218 | { | ||
219 | int r; | ||
220 | |||
221 | printk(KERN_DEBUG NAME ": NatSemi SCx200 Watchdog Driver\n"); | ||
222 | |||
223 | /* check that we have found the configuration block */ | ||
224 | if (!scx200_cb_present()) | ||
225 | return -ENODEV; | ||
226 | |||
227 | if (!request_region(scx200_cb_base + SCx200_WDT_OFFSET, | ||
228 | SCx200_WDT_SIZE, | ||
229 | "NatSemi SCx200 Watchdog")) { | ||
230 | printk(KERN_WARNING NAME ": watchdog I/O region busy\n"); | ||
231 | return -EBUSY; | ||
232 | } | ||
233 | |||
234 | scx200_wdt_update_margin(); | ||
235 | scx200_wdt_disable(); | ||
236 | |||
237 | sema_init(&open_semaphore, 1); | ||
238 | |||
239 | r = misc_register(&scx200_wdt_miscdev); | ||
240 | if (r) { | ||
241 | release_region(scx200_cb_base + SCx200_WDT_OFFSET, | ||
242 | SCx200_WDT_SIZE); | ||
243 | return r; | ||
244 | } | ||
245 | |||
246 | r = register_reboot_notifier(&scx200_wdt_notifier); | ||
247 | if (r) { | ||
248 | printk(KERN_ERR NAME ": unable to register reboot notifier"); | ||
249 | misc_deregister(&scx200_wdt_miscdev); | ||
250 | release_region(scx200_cb_base + SCx200_WDT_OFFSET, | ||
251 | SCx200_WDT_SIZE); | ||
252 | return r; | ||
253 | } | ||
254 | |||
255 | return 0; | ||
256 | } | ||
257 | |||
258 | static void __exit scx200_wdt_cleanup(void) | ||
259 | { | ||
260 | unregister_reboot_notifier(&scx200_wdt_notifier); | ||
261 | misc_deregister(&scx200_wdt_miscdev); | ||
262 | release_region(scx200_cb_base + SCx200_WDT_OFFSET, | ||
263 | SCx200_WDT_SIZE); | ||
264 | } | ||
265 | |||
266 | module_init(scx200_wdt_init); | ||
267 | module_exit(scx200_wdt_cleanup); | ||
268 | |||
269 | /* | ||
270 | Local variables: | ||
271 | compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules" | ||
272 | c-basic-offset: 8 | ||
273 | End: | ||
274 | */ | ||