eurotechwdt.c 11 KB

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  1. /*
  2. * Eurotech CPU-1220/1410 on board WDT driver
  3. *
  4. * (c) Copyright 2001 Ascensit <support@ascensit.com>
  5. * (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com>
  6. * (c) Copyright 2002 Rob Radez <rob@osinvestor.com>
  7. *
  8. * Based on wdt.c.
  9. * Original copyright messages:
  10. *
  11. * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
  12. * http://www.redhat.com
  13. *
  14. * This program is free software; you can redistribute it and/or
  15. * modify it under the terms of the GNU General Public License
  16. * as published by the Free Software Foundation; either version
  17. * 2 of the License, or (at your option) any later version.
  18. *
  19. * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
  20. * warranty for any of this software. This material is provided
  21. * "AS-IS" and at no charge.
  22. *
  23. * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>*
  24. */
  25. /* Changelog:
  26. *
  27. * 2002/04/25 - Rob Radez
  28. * clean up #includes
  29. * clean up locking
  30. * make __setup param unique
  31. * proper options in watchdog_info
  32. * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
  33. * add expect_close support
  34. *
  35. * 2001 - Rodolfo Giometti
  36. * Initial release
  37. *
  38. * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
  39. * Added Matt Domsch's nowayout module option.
  40. */
  41. #include <linux/interrupt.h>
  42. #include <linux/module.h>
  43. #include <linux/moduleparam.h>
  44. #include <linux/types.h>
  45. #include <linux/miscdevice.h>
  46. #include <linux/watchdog.h>
  47. #include <linux/fs.h>
  48. #include <linux/ioport.h>
  49. #include <linux/notifier.h>
  50. #include <linux/reboot.h>
  51. #include <linux/init.h>
  52. #include <asm/io.h>
  53. #include <asm/uaccess.h>
  54. #include <asm/system.h>
  55. static unsigned long eurwdt_is_open;
  56. static int eurwdt_timeout;
  57. static char eur_expect_close;
  58. /*
  59. * You must set these - there is no sane way to probe for this board.
  60. * You can use eurwdt=x,y to set these now.
  61. */
  62. static int io = 0x3f0;
  63. static int irq = 10;
  64. static char *ev = "int";
  65. #define WDT_TIMEOUT 60 /* 1 minute */
  66. static int nowayout = WATCHDOG_NOWAYOUT;
  67. module_param(nowayout, int, 0);
  68. MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
  69. /*
  70. * Some symbolic names
  71. */
  72. #define WDT_CTRL_REG 0x30
  73. #define WDT_OUTPIN_CFG 0xe2
  74. #define WDT_EVENT_INT 0x00
  75. #define WDT_EVENT_REBOOT 0x08
  76. #define WDT_UNIT_SEL 0xf1
  77. #define WDT_UNIT_SECS 0x80
  78. #define WDT_TIMEOUT_VAL 0xf2
  79. #define WDT_TIMER_CFG 0xf3
  80. module_param(io, int, 0);
  81. MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
  82. module_param(irq, int, 0);
  83. MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
  84. module_param(ev, charp, 0);
  85. MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
  86. /*
  87. * Programming support
  88. */
  89. static inline void eurwdt_write_reg(u8 index, u8 data)
  90. {
  91. outb(index, io);
  92. outb(data, io+1);
  93. }
  94. static inline void eurwdt_lock_chip(void)
  95. {
  96. outb(0xaa, io);
  97. }
  98. static inline void eurwdt_unlock_chip(void)
  99. {
  100. outb(0x55, io);
  101. eurwdt_write_reg(0x07, 0x08); /* set the logical device */
  102. }
  103. static inline void eurwdt_set_timeout(int timeout)
  104. {
  105. eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
  106. }
  107. static inline void eurwdt_disable_timer(void)
  108. {
  109. eurwdt_set_timeout(0);
  110. }
  111. static void eurwdt_activate_timer(void)
  112. {
  113. eurwdt_disable_timer();
  114. eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
  115. eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
  116. /* Setting interrupt line */
  117. if (irq == 2 || irq > 15 || irq < 0) {
  118. printk(KERN_ERR ": invalid irq number\n");
  119. irq = 0; /* if invalid we disable interrupt */
  120. }
  121. if (irq == 0)
  122. printk(KERN_INFO ": interrupt disabled\n");
  123. eurwdt_write_reg(WDT_TIMER_CFG, irq<<4);
  124. eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
  125. eurwdt_set_timeout(0); /* the default timeout */
  126. }
  127. /*
  128. * Kernel methods.
  129. */
  130. static irqreturn_t eurwdt_interrupt(int irq, void *dev_id)
  131. {
  132. printk(KERN_CRIT "timeout WDT timeout\n");
  133. #ifdef ONLY_TESTING
  134. printk(KERN_CRIT "Would Reboot.\n");
  135. #else
  136. printk(KERN_CRIT "Initiating system reboot.\n");
  137. emergency_restart();
  138. #endif
  139. return IRQ_HANDLED;
  140. }
  141. /**
  142. * eurwdt_ping:
  143. *
  144. * Reload counter one with the watchdog timeout.
  145. */
  146. static void eurwdt_ping(void)
  147. {
  148. /* Write the watchdog default value */
  149. eurwdt_set_timeout(eurwdt_timeout);
  150. }
  151. /**
  152. * eurwdt_write:
  153. * @file: file handle to the watchdog
  154. * @buf: buffer to write (unused as data does not matter here
  155. * @count: count of bytes
  156. * @ppos: pointer to the position to write. No seeks allowed
  157. *
  158. * A write to a watchdog device is defined as a keepalive signal. Any
  159. * write of data will do, as we we don't define content meaning.
  160. */
  161. static ssize_t eurwdt_write(struct file *file, const char __user *buf,
  162. size_t count, loff_t *ppos)
  163. {
  164. if (count) {
  165. if (!nowayout) {
  166. size_t i;
  167. eur_expect_close = 0;
  168. for (i = 0; i != count; i++) {
  169. char c;
  170. if(get_user(c, buf+i))
  171. return -EFAULT;
  172. if (c == 'V')
  173. eur_expect_close = 42;
  174. }
  175. }
  176. eurwdt_ping(); /* the default timeout */
  177. }
  178. return count;
  179. }
  180. /**
  181. * eurwdt_ioctl:
  182. * @inode: inode of the device
  183. * @file: file handle to the device
  184. * @cmd: watchdog command
  185. * @arg: argument pointer
  186. *
  187. * The watchdog API defines a common set of functions for all watchdogs
  188. * according to their available features.
  189. */
  190. static int eurwdt_ioctl(struct inode *inode, struct file *file,
  191. unsigned int cmd, unsigned long arg)
  192. {
  193. void __user *argp = (void __user *)arg;
  194. int __user *p = argp;
  195. static struct watchdog_info ident = {
  196. .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
  197. .firmware_version = 1,
  198. .identity = "WDT Eurotech CPU-1220/1410",
  199. };
  200. int time;
  201. int options, retval = -EINVAL;
  202. switch(cmd) {
  203. default:
  204. return -ENOTTY;
  205. case WDIOC_GETSUPPORT:
  206. return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
  207. case WDIOC_GETSTATUS:
  208. case WDIOC_GETBOOTSTATUS:
  209. return put_user(0, p);
  210. case WDIOC_KEEPALIVE:
  211. eurwdt_ping();
  212. return 0;
  213. case WDIOC_SETTIMEOUT:
  214. if (copy_from_user(&time, p, sizeof(int)))
  215. return -EFAULT;
  216. /* Sanity check */
  217. if (time < 0 || time > 255)
  218. return -EINVAL;
  219. eurwdt_timeout = time;
  220. eurwdt_set_timeout(time);
  221. /* Fall */
  222. case WDIOC_GETTIMEOUT:
  223. return put_user(eurwdt_timeout, p);
  224. case WDIOC_SETOPTIONS:
  225. if (get_user(options, p))
  226. return -EFAULT;
  227. if (options & WDIOS_DISABLECARD) {
  228. eurwdt_disable_timer();
  229. retval = 0;
  230. }
  231. if (options & WDIOS_ENABLECARD) {
  232. eurwdt_activate_timer();
  233. eurwdt_ping();
  234. retval = 0;
  235. }
  236. return retval;
  237. }
  238. }
  239. /**
  240. * eurwdt_open:
  241. * @inode: inode of device
  242. * @file: file handle to device
  243. *
  244. * The misc device has been opened. The watchdog device is single
  245. * open and on opening we load the counter.
  246. */
  247. static int eurwdt_open(struct inode *inode, struct file *file)
  248. {
  249. if (test_and_set_bit(0, &eurwdt_is_open))
  250. return -EBUSY;
  251. eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
  252. /* Activate the WDT */
  253. eurwdt_activate_timer();
  254. return nonseekable_open(inode, file);
  255. }
  256. /**
  257. * eurwdt_release:
  258. * @inode: inode to board
  259. * @file: file handle to board
  260. *
  261. * The watchdog has a configurable API. There is a religious dispute
  262. * between people who want their watchdog to be able to shut down and
  263. * those who want to be sure if the watchdog manager dies the machine
  264. * reboots. In the former case we disable the counters, in the latter
  265. * case you have to open it again very soon.
  266. */
  267. static int eurwdt_release(struct inode *inode, struct file *file)
  268. {
  269. if (eur_expect_close == 42) {
  270. eurwdt_disable_timer();
  271. } else {
  272. printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n");
  273. eurwdt_ping();
  274. }
  275. clear_bit(0, &eurwdt_is_open);
  276. eur_expect_close = 0;
  277. return 0;
  278. }
  279. /**
  280. * eurwdt_notify_sys:
  281. * @this: our notifier block
  282. * @code: the event being reported
  283. * @unused: unused
  284. *
  285. * Our notifier is called on system shutdowns. We want to turn the card
  286. * off at reboot otherwise the machine will reboot again during memory
  287. * test or worse yet during the following fsck. This would suck, in fact
  288. * trust me - if it happens it does suck.
  289. */
  290. static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
  291. void *unused)
  292. {
  293. if (code == SYS_DOWN || code == SYS_HALT) {
  294. /* Turn the card off */
  295. eurwdt_disable_timer();
  296. }
  297. return NOTIFY_DONE;
  298. }
  299. /*
  300. * Kernel Interfaces
  301. */
  302. static const struct file_operations eurwdt_fops = {
  303. .owner = THIS_MODULE,
  304. .llseek = no_llseek,
  305. .write = eurwdt_write,
  306. .ioctl = eurwdt_ioctl,
  307. .open = eurwdt_open,
  308. .release = eurwdt_release,
  309. };
  310. static struct miscdevice eurwdt_miscdev = {
  311. .minor = WATCHDOG_MINOR,
  312. .name = "watchdog",
  313. .fops = &eurwdt_fops,
  314. };
  315. /*
  316. * The WDT card needs to learn about soft shutdowns in order to
  317. * turn the timebomb registers off.
  318. */
  319. static struct notifier_block eurwdt_notifier = {
  320. .notifier_call = eurwdt_notify_sys,
  321. };
  322. /**
  323. * cleanup_module:
  324. *
  325. * Unload the watchdog. You cannot do this with any file handles open.
  326. * If your watchdog is set to continue ticking on close and you unload
  327. * it, well it keeps ticking. We won't get the interrupt but the board
  328. * will not touch PC memory so all is fine. You just have to load a new
  329. * module in 60 seconds or reboot.
  330. */
  331. static void __exit eurwdt_exit(void)
  332. {
  333. eurwdt_lock_chip();
  334. misc_deregister(&eurwdt_miscdev);
  335. unregister_reboot_notifier(&eurwdt_notifier);
  336. release_region(io, 2);
  337. free_irq(irq, NULL);
  338. }
  339. /**
  340. * eurwdt_init:
  341. *
  342. * Set up the WDT watchdog board. After grabbing the resources
  343. * we require we need also to unlock the device.
  344. * The open() function will actually kick the board off.
  345. */
  346. static int __init eurwdt_init(void)
  347. {
  348. int ret;
  349. ret = misc_register(&eurwdt_miscdev);
  350. if (ret) {
  351. printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
  352. WATCHDOG_MINOR);
  353. goto out;
  354. }
  355. ret = request_irq(irq, eurwdt_interrupt, IRQF_DISABLED, "eurwdt", NULL);
  356. if(ret) {
  357. printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
  358. goto outmisc;
  359. }
  360. if (!request_region(io, 2, "eurwdt")) {
  361. printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
  362. ret = -EBUSY;
  363. goto outirq;
  364. }
  365. ret = register_reboot_notifier(&eurwdt_notifier);
  366. if (ret) {
  367. printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);
  368. goto outreg;
  369. }
  370. eurwdt_unlock_chip();
  371. ret = 0;
  372. printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
  373. " - timeout event: %s\n",
  374. io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
  375. out:
  376. return ret;
  377. outreg:
  378. release_region(io, 2);
  379. outirq:
  380. free_irq(irq, NULL);
  381. outmisc:
  382. misc_deregister(&eurwdt_miscdev);
  383. goto out;
  384. }
  385. module_init(eurwdt_init);
  386. module_exit(eurwdt_exit);
  387. MODULE_AUTHOR("Rodolfo Giometti");
  388. MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
  389. MODULE_LICENSE("GPL");
  390. MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);