Blame view
drivers/watchdog/sbc60xxwdt.c
10.3 KB
1da177e4c Linux-2.6.12-rc2 |
1 2 3 |
/* * 60xx Single Board Computer Watchdog Timer driver for Linux 2.2.x * |
143a2e54b [WATCHDOG] More c... |
4 |
* Based on acquirewdt.c by Alan Cox. |
1da177e4c Linux-2.6.12-rc2 |
5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
* * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * The author does NOT admit liability nor provide warranty for * any of this software. This material is provided "AS-IS" in * the hope that it may be useful for others. * * (c) Copyright 2000 Jakob Oestergaard <jakob@unthought.net> * * 12/4 - 2000 [Initial revision] * 25/4 - 2000 Added /dev/watchdog support |
1780de414 [WATCHDOG 37/57] ... |
19 20 |
* 09/5 - 2001 [smj@oro.net] fixed fop_write to "return 1" * on success |
1da177e4c Linux-2.6.12-rc2 |
21 22 23 24 25 26 |
* 12/4 - 2002 [rob@osinvestor.com] eliminate fop_read * fix possible wdt_is_open race * add CONFIG_WATCHDOG_NOWAYOUT support * remove lock_kernel/unlock_kernel pairs * added KERN_* to printk's * got rid of extraneous comments |
1780de414 [WATCHDOG 37/57] ... |
27 28 29 30 31 |
* changed watchdog_info to correctly reflect what * the driver offers * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, * WDIOC_SETTIMEOUT, WDIOC_GETTIMEOUT, and * WDIOC_SETOPTIONS ioctls |
1da177e4c Linux-2.6.12-rc2 |
32 33 |
* 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces * use module_param |
1780de414 [WATCHDOG 37/57] ... |
34 35 |
* made timeout (the emulated heartbeat) a * module_param |
1da177e4c Linux-2.6.12-rc2 |
36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 |
* made the keepalive ping an internal subroutine * made wdt_stop and wdt_start module params * added extra printk's for startup problems * added MODULE_AUTHOR and MODULE_DESCRIPTION info * * * This WDT driver is different from the other Linux WDT * drivers in the following ways: * *) The driver will ping the watchdog by itself, because this * particular WDT has a very short timeout (one second) and it * would be insane to count on any userspace daemon always * getting scheduled within that time frame. * */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/timer.h> #include <linux/jiffies.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/fs.h> #include <linux/ioport.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/init.h> |
1780de414 [WATCHDOG 37/57] ... |
63 64 |
#include <linux/io.h> #include <linux/uaccess.h> |
1da177e4c Linux-2.6.12-rc2 |
65 |
|
1da177e4c Linux-2.6.12-rc2 |
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 |
#include <asm/system.h> #define OUR_NAME "sbc60xxwdt" #define PFX OUR_NAME ": " /* * You must set these - The driver cannot probe for the settings */ static int wdt_stop = 0x45; module_param(wdt_stop, int, 0); MODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)"); static int wdt_start = 0x443; module_param(wdt_start, int, 0); MODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)"); /* * The 60xx board can use watchdog timeout values from one second * to several minutes. The default is one second, so if we reset * the watchdog every ~250ms we should be safe. */ #define WDT_INTERVAL (HZ/4+1) /* * We must not require too good response from the userspace daemon. * Here we require the userspace daemon to send us a heartbeat * char to /dev/watchdog every 30 seconds. * If the daemon pulses us every 25 seconds, we can still afford * a 5 second scheduling delay on the (high priority) daemon. That * should be sufficient for a box under any load. */ #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ |
1780de414 [WATCHDOG 37/57] ... |
101 102 |
static int timeout = WATCHDOG_TIMEOUT; /* in seconds, multiplied by HZ to get seconds to wait for a ping */ |
1da177e4c Linux-2.6.12-rc2 |
103 |
module_param(timeout, int, 0); |
1780de414 [WATCHDOG 37/57] ... |
104 105 106 |
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); |
1da177e4c Linux-2.6.12-rc2 |
107 |
|
4bfdf3783 [PATCH] consolida... |
108 |
static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4c Linux-2.6.12-rc2 |
109 |
module_param(nowayout, int, 0); |
1780de414 [WATCHDOG 37/57] ... |
110 111 112 |
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
1da177e4c Linux-2.6.12-rc2 |
113 114 |
static void wdt_timer_ping(unsigned long); |
82eb7c505 [WATCHDOG] timers... |
115 |
static DEFINE_TIMER(timer, wdt_timer_ping, 0, 0); |
1da177e4c Linux-2.6.12-rc2 |
116 117 118 119 120 121 122 123 124 125 126 127 128 |
static unsigned long next_heartbeat; static unsigned long wdt_is_open; static char wdt_expect_close; /* * Whack the dog */ static void wdt_timer_ping(unsigned long data) { /* If we got a heartbeat pulse within the WDT_US_INTERVAL * we agree to ping the WDT */ |
1780de414 [WATCHDOG 37/57] ... |
129 |
if (time_before(jiffies, next_heartbeat)) { |
1da177e4c Linux-2.6.12-rc2 |
130 131 132 |
/* Ping the WDT by reading from wdt_start */ inb_p(wdt_start); /* Re-set the timer interval */ |
82eb7c505 [WATCHDOG] timers... |
133 |
mod_timer(&timer, jiffies + WDT_INTERVAL); |
1780de414 [WATCHDOG 37/57] ... |
134 135 136 137 |
} else printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog "); |
1da177e4c Linux-2.6.12-rc2 |
138 139 140 141 142 143 144 145 146 147 148 |
} /* * Utility routines */ static void wdt_startup(void) { next_heartbeat = jiffies + (timeout * HZ); /* Start the timer */ |
82eb7c505 [WATCHDOG] timers... |
149 |
mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4c Linux-2.6.12-rc2 |
150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 |
printk(KERN_INFO PFX "Watchdog timer is now enabled. "); } static void wdt_turnoff(void) { /* Stop the timer */ del_timer(&timer); inb_p(wdt_stop); printk(KERN_INFO PFX "Watchdog timer is now disabled... "); } static void wdt_keepalive(void) { /* user land ping */ next_heartbeat = jiffies + (timeout * HZ); } /* * /dev/watchdog handling */ |
1780de414 [WATCHDOG 37/57] ... |
172 173 |
static ssize_t fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
1da177e4c Linux-2.6.12-rc2 |
174 175 |
{ /* See if we got the magic character 'V' and reload the timer */ |
1780de414 [WATCHDOG 37/57] ... |
176 177 |
if (count) { if (!nowayout) { |
1da177e4c Linux-2.6.12-rc2 |
178 |
size_t ofs; |
1780de414 [WATCHDOG 37/57] ... |
179 180 |
/* note: just in case someone wrote the magic character five months ago... */ |
1da177e4c Linux-2.6.12-rc2 |
181 |
wdt_expect_close = 0; |
1780de414 [WATCHDOG 37/57] ... |
182 183 184 |
/* scan to see whether or not we got the magic character */ for (ofs = 0; ofs != count; ofs++) { |
1da177e4c Linux-2.6.12-rc2 |
185 |
char c; |
7944d3a5a [WATCHDOG] more c... |
186 |
if (get_user(c, buf + ofs)) |
1da177e4c Linux-2.6.12-rc2 |
187 |
return -EFAULT; |
1780de414 [WATCHDOG 37/57] ... |
188 |
if (c == 'V') |
1da177e4c Linux-2.6.12-rc2 |
189 190 191 |
wdt_expect_close = 42; } } |
1780de414 [WATCHDOG 37/57] ... |
192 193 |
/* Well, anyhow someone wrote to us, we should return that favour */ |
1da177e4c Linux-2.6.12-rc2 |
194 195 196 197 |
wdt_keepalive(); } return count; } |
1780de414 [WATCHDOG 37/57] ... |
198 |
static int fop_open(struct inode *inode, struct file *file) |
1da177e4c Linux-2.6.12-rc2 |
199 |
{ |
1da177e4c Linux-2.6.12-rc2 |
200 |
/* Just in case we're already talking to someone... */ |
1780de414 [WATCHDOG 37/57] ... |
201 |
if (test_and_set_bit(0, &wdt_is_open)) |
1da177e4c Linux-2.6.12-rc2 |
202 203 204 205 206 207 208 |
return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Good, fire up the show */ wdt_startup(); |
6abe78bf1 [WATCHDOG] Return... |
209 |
return nonseekable_open(inode, file); |
1da177e4c Linux-2.6.12-rc2 |
210 |
} |
1780de414 [WATCHDOG 37/57] ... |
211 |
static int fop_close(struct inode *inode, struct file *file) |
1da177e4c Linux-2.6.12-rc2 |
212 |
{ |
1780de414 [WATCHDOG 37/57] ... |
213 |
if (wdt_expect_close == 42) |
1da177e4c Linux-2.6.12-rc2 |
214 215 216 |
wdt_turnoff(); else { del_timer(&timer); |
1780de414 [WATCHDOG 37/57] ... |
217 218 219 |
printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT! "); |
1da177e4c Linux-2.6.12-rc2 |
220 221 222 223 224 |
} clear_bit(0, &wdt_is_open); wdt_expect_close = 0; return 0; } |
1780de414 [WATCHDOG 37/57] ... |
225 |
static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4c Linux-2.6.12-rc2 |
226 227 228 |
{ void __user *argp = (void __user *)arg; int __user *p = argp; |
1780de414 [WATCHDOG 37/57] ... |
229 230 231 |
static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, |
1da177e4c Linux-2.6.12-rc2 |
232 233 234 |
.firmware_version = 1, .identity = "SBC60xx", }; |
1780de414 [WATCHDOG 37/57] ... |
235 |
switch (cmd) { |
1780de414 [WATCHDOG 37/57] ... |
236 |
case WDIOC_GETSUPPORT: |
7944d3a5a [WATCHDOG] more c... |
237 |
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; |
1780de414 [WATCHDOG 37/57] ... |
238 239 240 |
case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); |
1780de414 [WATCHDOG 37/57] ... |
241 |
case WDIOC_SETOPTIONS: |
1da177e4c Linux-2.6.12-rc2 |
242 |
{ |
1780de414 [WATCHDOG 37/57] ... |
243 244 245 246 247 248 |
int new_options, retval = -EINVAL; if (get_user(new_options, p)) return -EFAULT; if (new_options & WDIOS_DISABLECARD) { wdt_turnoff(); retval = 0; |
1da177e4c Linux-2.6.12-rc2 |
249 |
} |
1780de414 [WATCHDOG 37/57] ... |
250 251 252 |
if (new_options & WDIOS_ENABLECARD) { wdt_startup(); retval = 0; |
1da177e4c Linux-2.6.12-rc2 |
253 |
} |
1780de414 [WATCHDOG 37/57] ... |
254 255 |
return retval; } |
0c06090c9 [WATCHDOG] Coding... |
256 257 258 |
case WDIOC_KEEPALIVE: wdt_keepalive(); return 0; |
1780de414 [WATCHDOG 37/57] ... |
259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 |
case WDIOC_SETTIMEOUT: { int new_timeout; if (get_user(new_timeout, p)) return -EFAULT; /* arbitrary upper limit */ if (new_timeout < 1 || new_timeout > 3600) return -EINVAL; timeout = new_timeout; wdt_keepalive(); /* Fall through */ } case WDIOC_GETTIMEOUT: return put_user(timeout, p); |
0c06090c9 [WATCHDOG] Coding... |
274 275 |
default: return -ENOTTY; |
1da177e4c Linux-2.6.12-rc2 |
276 277 |
} } |
62322d255 [PATCH] make more... |
278 |
static const struct file_operations wdt_fops = { |
1da177e4c Linux-2.6.12-rc2 |
279 280 281 282 283 |
.owner = THIS_MODULE, .llseek = no_llseek, .write = fop_write, .open = fop_open, .release = fop_close, |
1780de414 [WATCHDOG 37/57] ... |
284 |
.unlocked_ioctl = fop_ioctl, |
1da177e4c Linux-2.6.12-rc2 |
285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 |
}; static struct miscdevice wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &wdt_fops, }; /* * Notifier for system down */ static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { |
1780de414 [WATCHDOG 37/57] ... |
300 |
if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4c Linux-2.6.12-rc2 |
301 302 303 304 305 306 307 308 |
wdt_turnoff(); return NOTIFY_DONE; } /* * The WDT needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ |
1780de414 [WATCHDOG 37/57] ... |
309 |
static struct notifier_block wdt_notifier = { |
1da177e4c Linux-2.6.12-rc2 |
310 311 312 313 314 315 316 317 318 319 320 321 |
.notifier_call = wdt_notify_sys, }; static void __exit sbc60xxwdt_unload(void) { wdt_turnoff(); /* Deregister */ misc_deregister(&wdt_miscdev); unregister_reboot_notifier(&wdt_notifier); if ((wdt_stop != 0x45) && (wdt_stop != wdt_start)) |
1780de414 [WATCHDOG 37/57] ... |
322 323 |
release_region(wdt_stop, 1); release_region(wdt_start, 1); |
1da177e4c Linux-2.6.12-rc2 |
324 325 326 327 328 |
} static int __init sbc60xxwdt_init(void) { int rc = -EBUSY; |
1780de414 [WATCHDOG 37/57] ... |
329 |
if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */ |
1da177e4c Linux-2.6.12-rc2 |
330 |
timeout = WATCHDOG_TIMEOUT; |
1780de414 [WATCHDOG 37/57] ... |
331 332 333 334 335 |
printk(KERN_INFO PFX "timeout value must be 1 <= x <= 3600, using %d ", timeout); } |
1da177e4c Linux-2.6.12-rc2 |
336 |
|
1780de414 [WATCHDOG 37/57] ... |
337 |
if (!request_region(wdt_start, 1, "SBC 60XX WDT")) { |
1da177e4c Linux-2.6.12-rc2 |
338 339 340 341 342 343 344 345 |
printk(KERN_ERR PFX "I/O address 0x%04x already in use ", wdt_start); rc = -EIO; goto err_out; } /* We cannot reserve 0x45 - the kernel already has! */ |
1780de414 [WATCHDOG 37/57] ... |
346 347 348 349 350 351 |
if (wdt_stop != 0x45 && wdt_stop != wdt_start) { if (!request_region(wdt_stop, 1, "SBC 60XX WDT")) { printk(KERN_ERR PFX "I/O address 0x%04x already in use ", wdt_stop); |
1da177e4c Linux-2.6.12-rc2 |
352 353 354 355 |
rc = -EIO; goto err_out_region1; } } |
c6cb13aea [WATCHDOG] misc_r... |
356 |
rc = register_reboot_notifier(&wdt_notifier); |
1780de414 [WATCHDOG 37/57] ... |
357 358 359 360 |
if (rc) { printk(KERN_ERR PFX "cannot register reboot notifier (err=%d) ", rc); |
1da177e4c Linux-2.6.12-rc2 |
361 362 |
goto err_out_region2; } |
c6cb13aea [WATCHDOG] misc_r... |
363 |
rc = misc_register(&wdt_miscdev); |
1780de414 [WATCHDOG 37/57] ... |
364 365 366 367 368 |
if (rc) { printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d) ", wdt_miscdev.minor, rc); |
c6cb13aea [WATCHDOG] misc_r... |
369 |
goto err_out_reboot; |
1da177e4c Linux-2.6.12-rc2 |
370 |
} |
a77dba7e4 [WATCHDOG] Some m... |
371 372 373 374 |
printk(KERN_INFO PFX "WDT driver for 60XX single board computer initialised. " "timeout=%d sec (nowayout=%d) ", timeout, nowayout); |
1da177e4c Linux-2.6.12-rc2 |
375 376 |
return 0; |
c6cb13aea [WATCHDOG] misc_r... |
377 378 |
err_out_reboot: unregister_reboot_notifier(&wdt_notifier); |
1da177e4c Linux-2.6.12-rc2 |
379 |
err_out_region2: |
1780de414 [WATCHDOG 37/57] ... |
380 381 |
if (wdt_stop != 0x45 && wdt_stop != wdt_start) release_region(wdt_stop, 1); |
1da177e4c Linux-2.6.12-rc2 |
382 |
err_out_region1: |
1780de414 [WATCHDOG 37/57] ... |
383 |
release_region(wdt_start, 1); |
1da177e4c Linux-2.6.12-rc2 |
384 385 386 387 388 389 390 391 392 393 394 |
err_out: return rc; } module_init(sbc60xxwdt_init); module_exit(sbc60xxwdt_unload); MODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>"); MODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |