diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
---|---|---|
committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/acquirewdt.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/acquirewdt.c')
-rw-r--r-- | drivers/watchdog/acquirewdt.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/drivers/watchdog/acquirewdt.c b/drivers/watchdog/acquirewdt.c new file mode 100644 index 000000000000..85269c365a10 --- /dev/null +++ b/drivers/watchdog/acquirewdt.c | |||
@@ -0,0 +1,348 @@ | |||
1 | /* | ||
2 | * Acquire Single Board Computer Watchdog Timer driver | ||
3 | * | ||
4 | * Based on wdt.c. Original copyright messages: | ||
5 | * | ||
6 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | ||
7 | * http://www.redhat.com | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or | ||
10 | * modify it under the terms of the GNU General Public License | ||
11 | * as published by the Free Software Foundation; either version | ||
12 | * 2 of the License, or (at your option) any later version. | ||
13 | * | ||
14 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | ||
15 | * warranty for any of this software. This material is provided | ||
16 | * "AS-IS" and at no charge. | ||
17 | * | ||
18 | * (c) Copyright 1995 Alan Cox <alan@redhat.com> | ||
19 | * | ||
20 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | ||
21 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | ||
22 | * Can't add timeout - driver doesn't allow changing value | ||
23 | */ | ||
24 | |||
25 | /* | ||
26 | * Theory of Operation: | ||
27 | * The Watch-Dog Timer is provided to ensure that standalone | ||
28 | * Systems can always recover from catastrophic conditions that | ||
29 | * caused the CPU to crash. This condition may have occured by | ||
30 | * external EMI or a software bug. When the CPU stops working | ||
31 | * correctly, hardware on the board will either perform a hardware | ||
32 | * reset (cold boot) or a non-maskable interrupt (NMI) to bring the | ||
33 | * system back to a known state. | ||
34 | * | ||
35 | * The Watch-Dog Timer is controlled by two I/O Ports. | ||
36 | * 443 hex - Read - Enable or refresh the Watch-Dog Timer | ||
37 | * 043 hex - Read - Disable the Watch-Dog Timer | ||
38 | * | ||
39 | * To enable the Watch-Dog Timer, a read from I/O port 443h must | ||
40 | * be performed. This will enable and activate the countdown timer | ||
41 | * which will eventually time out and either reset the CPU or cause | ||
42 | * an NMI depending on the setting of a jumper. To ensure that this | ||
43 | * reset condition does not occur, the Watch-Dog Timer must be | ||
44 | * periodically refreshed by reading the same I/O port 443h. | ||
45 | * The Watch-Dog Timer is disabled by reading I/O port 043h. | ||
46 | * | ||
47 | * The Watch-Dog Timer Time-Out Period is set via jumpers. | ||
48 | * It can be 1, 2, 10, 20, 110 or 220 seconds. | ||
49 | */ | ||
50 | |||
51 | /* | ||
52 | * Includes, defines, variables, module parameters, ... | ||
53 | */ | ||
54 | |||
55 | /* Includes */ | ||
56 | #include <linux/module.h> /* For module specific items */ | ||
57 | #include <linux/moduleparam.h> /* For new moduleparam's */ | ||
58 | #include <linux/types.h> /* For standard types (like size_t) */ | ||
59 | #include <linux/errno.h> /* For the -ENODEV/... values */ | ||
60 | #include <linux/kernel.h> /* For printk/panic/... */ | ||
61 | #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */ | ||
62 | #include <linux/watchdog.h> /* For the watchdog specific items */ | ||
63 | #include <linux/fs.h> /* For file operations */ | ||
64 | #include <linux/ioport.h> /* For io-port access */ | ||
65 | #include <linux/platform_device.h> /* For platform_driver framework */ | ||
66 | #include <linux/init.h> /* For __init/__exit/... */ | ||
67 | |||
68 | #include <asm/uaccess.h> /* For copy_to_user/put_user/... */ | ||
69 | #include <asm/io.h> /* For inb/outb/... */ | ||
70 | |||
71 | /* Module information */ | ||
72 | #define DRV_NAME "acquirewdt" | ||
73 | #define PFX DRV_NAME ": " | ||
74 | #define WATCHDOG_NAME "Acquire WDT" | ||
75 | #define WATCHDOG_HEARTBEAT 0 /* There is no way to see what the correct time-out period is */ | ||
76 | |||
77 | /* internal variables */ | ||
78 | static struct platform_device *acq_platform_device; /* the watchdog platform device */ | ||
79 | static unsigned long acq_is_open; | ||
80 | static char expect_close; | ||
81 | |||
82 | /* module parameters */ | ||
83 | static int wdt_stop = 0x43; /* You must set this - there is no sane way to probe for this board. */ | ||
84 | module_param(wdt_stop, int, 0); | ||
85 | MODULE_PARM_DESC(wdt_stop, "Acquire WDT 'stop' io port (default 0x43)"); | ||
86 | |||
87 | static int wdt_start = 0x443; /* You must set this - there is no sane way to probe for this board. */ | ||
88 | module_param(wdt_start, int, 0); | ||
89 | MODULE_PARM_DESC(wdt_start, "Acquire WDT 'start' io port (default 0x443)"); | ||
90 | |||
91 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
92 | module_param(nowayout, int, 0); | ||
93 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
94 | |||
95 | /* | ||
96 | * Watchdog Operations | ||
97 | */ | ||
98 | |||
99 | static void acq_keepalive(void) | ||
100 | { | ||
101 | /* Write a watchdog value */ | ||
102 | inb_p(wdt_start); | ||
103 | } | ||
104 | |||
105 | static void acq_stop(void) | ||
106 | { | ||
107 | /* Turn the card off */ | ||
108 | inb_p(wdt_stop); | ||
109 | } | ||
110 | |||
111 | /* | ||
112 | * /dev/watchdog handling | ||
113 | */ | ||
114 | |||
115 | static ssize_t acq_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | ||
116 | { | ||
117 | /* See if we got the magic character 'V' and reload the timer */ | ||
118 | if(count) { | ||
119 | if (!nowayout) { | ||
120 | size_t i; | ||
121 | |||
122 | /* note: just in case someone wrote the magic character | ||
123 | * five months ago... */ | ||
124 | expect_close = 0; | ||
125 | |||
126 | /* scan to see whether or not we got the magic character */ | ||
127 | for (i = 0; i != count; i++) { | ||
128 | char c; | ||
129 | if (get_user(c, buf + i)) | ||
130 | return -EFAULT; | ||
131 | if (c == 'V') | ||
132 | expect_close = 42; | ||
133 | } | ||
134 | } | ||
135 | |||
136 | /* Well, anyhow someone wrote to us, we should return that favour */ | ||
137 | acq_keepalive(); | ||
138 | } | ||
139 | return count; | ||
140 | } | ||
141 | |||
142 | static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
143 | unsigned long arg) | ||
144 | { | ||
145 | int options, retval = -EINVAL; | ||
146 | void __user *argp = (void __user *)arg; | ||
147 | int __user *p = argp; | ||
148 | static struct watchdog_info ident = | ||
149 | { | ||
150 | .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | ||
151 | .firmware_version = 1, | ||
152 | .identity = WATCHDOG_NAME, | ||
153 | }; | ||
154 | |||
155 | switch(cmd) | ||
156 | { | ||
157 | case WDIOC_GETSUPPORT: | ||
158 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | ||
159 | |||
160 | case WDIOC_GETSTATUS: | ||
161 | case WDIOC_GETBOOTSTATUS: | ||
162 | return put_user(0, p); | ||
163 | |||
164 | case WDIOC_KEEPALIVE: | ||
165 | acq_keepalive(); | ||
166 | return 0; | ||
167 | |||
168 | case WDIOC_GETTIMEOUT: | ||
169 | return put_user(WATCHDOG_HEARTBEAT, p); | ||
170 | |||
171 | case WDIOC_SETOPTIONS: | ||
172 | { | ||
173 | if (get_user(options, p)) | ||
174 | return -EFAULT; | ||
175 | |||
176 | if (options & WDIOS_DISABLECARD) | ||
177 | { | ||
178 | acq_stop(); | ||
179 | retval = 0; | ||
180 | } | ||
181 | |||
182 | if (options & WDIOS_ENABLECARD) | ||
183 | { | ||
184 | acq_keepalive(); | ||
185 | retval = 0; | ||
186 | } | ||
187 | |||
188 | return retval; | ||
189 | } | ||
190 | |||
191 | default: | ||
192 | return -ENOTTY; | ||
193 | } | ||
194 | } | ||
195 | |||
196 | static int acq_open(struct inode *inode, struct file *file) | ||
197 | { | ||
198 | if (test_and_set_bit(0, &acq_is_open)) | ||
199 | return -EBUSY; | ||
200 | |||
201 | if (nowayout) | ||
202 | __module_get(THIS_MODULE); | ||
203 | |||
204 | /* Activate */ | ||
205 | acq_keepalive(); | ||
206 | return nonseekable_open(inode, file); | ||
207 | } | ||
208 | |||
209 | static int acq_close(struct inode *inode, struct file *file) | ||
210 | { | ||
211 | if (expect_close == 42) { | ||
212 | acq_stop(); | ||
213 | } else { | ||
214 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | ||
215 | acq_keepalive(); | ||
216 | } | ||
217 | clear_bit(0, &acq_is_open); | ||
218 | expect_close = 0; | ||
219 | return 0; | ||
220 | } | ||
221 | |||
222 | /* | ||
223 | * Kernel Interfaces | ||
224 | */ | ||
225 | |||
226 | static const struct file_operations acq_fops = { | ||
227 | .owner = THIS_MODULE, | ||
228 | .llseek = no_llseek, | ||
229 | .write = acq_write, | ||
230 | .ioctl = acq_ioctl, | ||
231 | .open = acq_open, | ||
232 | .release = acq_close, | ||
233 | }; | ||
234 | |||
235 | static struct miscdevice acq_miscdev = { | ||
236 | .minor = WATCHDOG_MINOR, | ||
237 | .name = "watchdog", | ||
238 | .fops = &acq_fops, | ||
239 | }; | ||
240 | |||
241 | /* | ||
242 | * Init & exit routines | ||
243 | */ | ||
244 | |||
245 | static int __devinit acq_probe(struct platform_device *dev) | ||
246 | { | ||
247 | int ret; | ||
248 | |||
249 | if (wdt_stop != wdt_start) { | ||
250 | if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { | ||
251 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", | ||
252 | wdt_stop); | ||
253 | ret = -EIO; | ||
254 | goto out; | ||
255 | } | ||
256 | } | ||
257 | |||
258 | if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { | ||
259 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", | ||
260 | wdt_start); | ||
261 | ret = -EIO; | ||
262 | goto unreg_stop; | ||
263 | } | ||
264 | |||
265 | ret = misc_register(&acq_miscdev); | ||
266 | if (ret != 0) { | ||
267 | printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
268 | WATCHDOG_MINOR, ret); | ||
269 | goto unreg_regions; | ||
270 | } | ||
271 | |||
272 | printk (KERN_INFO PFX "initialized. (nowayout=%d)\n", | ||
273 | nowayout); | ||
274 | |||
275 | return 0; | ||
276 | |||
277 | unreg_regions: | ||
278 | release_region(wdt_start, 1); | ||
279 | unreg_stop: | ||
280 | if (wdt_stop != wdt_start) | ||
281 | release_region(wdt_stop, 1); | ||
282 | out: | ||
283 | return ret; | ||
284 | } | ||
285 | |||
286 | static int __devexit acq_remove(struct platform_device *dev) | ||
287 | { | ||
288 | misc_deregister(&acq_miscdev); | ||
289 | release_region(wdt_start,1); | ||
290 | if(wdt_stop != wdt_start) | ||
291 | release_region(wdt_stop,1); | ||
292 | |||
293 | return 0; | ||
294 | } | ||
295 | |||
296 | static void acq_shutdown(struct platform_device *dev) | ||
297 | { | ||
298 | /* Turn the WDT off if we have a soft shutdown */ | ||
299 | acq_stop(); | ||
300 | } | ||
301 | |||
302 | static struct platform_driver acquirewdt_driver = { | ||
303 | .probe = acq_probe, | ||
304 | .remove = __devexit_p(acq_remove), | ||
305 | .shutdown = acq_shutdown, | ||
306 | .driver = { | ||
307 | .owner = THIS_MODULE, | ||
308 | .name = DRV_NAME, | ||
309 | }, | ||
310 | }; | ||
311 | |||
312 | static int __init acq_init(void) | ||
313 | { | ||
314 | int err; | ||
315 | |||
316 | printk(KERN_INFO "WDT driver for Acquire single board computer initialising.\n"); | ||
317 | |||
318 | err = platform_driver_register(&acquirewdt_driver); | ||
319 | if (err) | ||
320 | return err; | ||
321 | |||
322 | acq_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0); | ||
323 | if (IS_ERR(acq_platform_device)) { | ||
324 | err = PTR_ERR(acq_platform_device); | ||
325 | goto unreg_platform_driver; | ||
326 | } | ||
327 | |||
328 | return 0; | ||
329 | |||
330 | unreg_platform_driver: | ||
331 | platform_driver_unregister(&acquirewdt_driver); | ||
332 | return err; | ||
333 | } | ||
334 | |||
335 | static void __exit acq_exit(void) | ||
336 | { | ||
337 | platform_device_unregister(acq_platform_device); | ||
338 | platform_driver_unregister(&acquirewdt_driver); | ||
339 | printk(KERN_INFO PFX "Watchdog Module Unloaded.\n"); | ||
340 | } | ||
341 | |||
342 | module_init(acq_init); | ||
343 | module_exit(acq_exit); | ||
344 | |||
345 | MODULE_AUTHOR("David Woodhouse"); | ||
346 | MODULE_DESCRIPTION("Acquire Inc. Single Board Computer Watchdog Timer driver"); | ||
347 | MODULE_LICENSE("GPL"); | ||
348 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||