Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 26 | /* Changelog: |
| 27 | * |
| 28 | * 2002/04/25 - Rob Radez |
| 29 | * clean up #includes |
| 30 | * clean up locking |
| 31 | * make __setup param unique |
| 32 | * proper options in watchdog_info |
| 33 | * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls |
| 34 | * add expect_close support |
| 35 | * |
| 36 | * 2001 - Rodolfo Giometti |
| 37 | * Initial release |
| 38 | * |
| 39 | * 2002.05.30 - Joel Becker <joel.becker@oracle.com> |
| 40 | * Added Matt Domsch's nowayout module option. |
| 41 | */ |
| 42 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/interrupt.h> |
| 44 | #include <linux/module.h> |
| 45 | #include <linux/moduleparam.h> |
| 46 | #include <linux/types.h> |
| 47 | #include <linux/miscdevice.h> |
| 48 | #include <linux/watchdog.h> |
| 49 | #include <linux/fs.h> |
| 50 | #include <linux/ioport.h> |
| 51 | #include <linux/notifier.h> |
| 52 | #include <linux/reboot.h> |
| 53 | #include <linux/init.h> |
| 54 | |
| 55 | #include <asm/io.h> |
| 56 | #include <asm/uaccess.h> |
| 57 | #include <asm/system.h> |
| 58 | |
| 59 | static unsigned long eurwdt_is_open; |
| 60 | static int eurwdt_timeout; |
| 61 | static char eur_expect_close; |
| 62 | |
| 63 | /* |
| 64 | * You must set these - there is no sane way to probe for this board. |
| 65 | * You can use eurwdt=x,y to set these now. |
| 66 | */ |
| 67 | |
| 68 | static int io = 0x3f0; |
| 69 | static int irq = 10; |
| 70 | static char *ev = "int"; |
| 71 | |
| 72 | #define WDT_TIMEOUT 60 /* 1 minute */ |
| 73 | |
Andrey Panin | 4bfdf37 | 2005-07-27 11:43:58 -0700 | [diff] [blame] | 74 | static int nowayout = WATCHDOG_NOWAYOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | module_param(nowayout, int, 0); |
| 76 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); |
| 77 | |
| 78 | /* |
| 79 | * Some symbolic names |
| 80 | */ |
| 81 | |
| 82 | #define WDT_CTRL_REG 0x30 |
| 83 | #define WDT_OUTPIN_CFG 0xe2 |
| 84 | #define WDT_EVENT_INT 0x00 |
| 85 | #define WDT_EVENT_REBOOT 0x08 |
| 86 | #define WDT_UNIT_SEL 0xf1 |
| 87 | #define WDT_UNIT_SECS 0x80 |
| 88 | #define WDT_TIMEOUT_VAL 0xf2 |
| 89 | #define WDT_TIMER_CFG 0xf3 |
| 90 | |
| 91 | |
| 92 | module_param(io, int, 0); |
| 93 | MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)"); |
| 94 | module_param(irq, int, 0); |
| 95 | MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)"); |
| 96 | module_param(ev, charp, 0); |
| 97 | MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')"); |
| 98 | |
| 99 | |
| 100 | /* |
| 101 | * Programming support |
| 102 | */ |
| 103 | |
| 104 | static inline void eurwdt_write_reg(u8 index, u8 data) |
| 105 | { |
| 106 | outb(index, io); |
| 107 | outb(data, io+1); |
| 108 | } |
| 109 | |
| 110 | static inline void eurwdt_lock_chip(void) |
| 111 | { |
| 112 | outb(0xaa, io); |
| 113 | } |
| 114 | |
| 115 | static inline void eurwdt_unlock_chip(void) |
| 116 | { |
| 117 | outb(0x55, io); |
| 118 | eurwdt_write_reg(0x07, 0x08); /* set the logical device */ |
| 119 | } |
| 120 | |
| 121 | static inline void eurwdt_set_timeout(int timeout) |
| 122 | { |
| 123 | eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout); |
| 124 | } |
| 125 | |
| 126 | static inline void eurwdt_disable_timer(void) |
| 127 | { |
| 128 | eurwdt_set_timeout(0); |
| 129 | } |
| 130 | |
| 131 | static void eurwdt_activate_timer(void) |
| 132 | { |
| 133 | eurwdt_disable_timer(); |
| 134 | eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */ |
| 135 | eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT); |
| 136 | |
| 137 | /* Setting interrupt line */ |
| 138 | if (irq == 2 || irq > 15 || irq < 0) { |
| 139 | printk(KERN_ERR ": invalid irq number\n"); |
| 140 | irq = 0; /* if invalid we disable interrupt */ |
| 141 | } |
| 142 | if (irq == 0) |
| 143 | printk(KERN_INFO ": interrupt disabled\n"); |
| 144 | |
| 145 | eurwdt_write_reg(WDT_TIMER_CFG, irq<<4); |
| 146 | |
| 147 | eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */ |
| 148 | eurwdt_set_timeout(0); /* the default timeout */ |
| 149 | } |
| 150 | |
| 151 | |
| 152 | /* |
| 153 | * Kernel methods. |
| 154 | */ |
| 155 | |
| 156 | static irqreturn_t eurwdt_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 157 | { |
| 158 | printk(KERN_CRIT "timeout WDT timeout\n"); |
| 159 | |
| 160 | #ifdef ONLY_TESTING |
| 161 | printk(KERN_CRIT "Would Reboot.\n"); |
| 162 | #else |
| 163 | printk(KERN_CRIT "Initiating system reboot.\n"); |
Andrew Morton | cc1d3a9 | 2005-07-26 21:41:37 -0700 | [diff] [blame] | 164 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | #endif |
| 166 | return IRQ_HANDLED; |
| 167 | } |
| 168 | |
| 169 | |
| 170 | /** |
| 171 | * eurwdt_ping: |
| 172 | * |
| 173 | * Reload counter one with the watchdog timeout. |
| 174 | */ |
| 175 | |
| 176 | static void eurwdt_ping(void) |
| 177 | { |
| 178 | /* Write the watchdog default value */ |
| 179 | eurwdt_set_timeout(eurwdt_timeout); |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * eurwdt_write: |
| 184 | * @file: file handle to the watchdog |
| 185 | * @buf: buffer to write (unused as data does not matter here |
| 186 | * @count: count of bytes |
| 187 | * @ppos: pointer to the position to write. No seeks allowed |
| 188 | * |
| 189 | * A write to a watchdog device is defined as a keepalive signal. Any |
| 190 | * write of data will do, as we we don't define content meaning. |
| 191 | */ |
| 192 | |
| 193 | static ssize_t eurwdt_write(struct file *file, const char __user *buf, |
| 194 | size_t count, loff_t *ppos) |
| 195 | { |
| 196 | if (count) { |
| 197 | if (!nowayout) { |
| 198 | size_t i; |
| 199 | |
| 200 | eur_expect_close = 0; |
| 201 | |
| 202 | for (i = 0; i != count; i++) { |
| 203 | char c; |
| 204 | if(get_user(c, buf+i)) |
| 205 | return -EFAULT; |
| 206 | if (c == 'V') |
| 207 | eur_expect_close = 42; |
| 208 | } |
| 209 | } |
| 210 | eurwdt_ping(); /* the default timeout */ |
| 211 | } |
| 212 | |
| 213 | return count; |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * eurwdt_ioctl: |
| 218 | * @inode: inode of the device |
| 219 | * @file: file handle to the device |
| 220 | * @cmd: watchdog command |
| 221 | * @arg: argument pointer |
| 222 | * |
| 223 | * The watchdog API defines a common set of functions for all watchdogs |
| 224 | * according to their available features. |
| 225 | */ |
| 226 | |
| 227 | static int eurwdt_ioctl(struct inode *inode, struct file *file, |
| 228 | unsigned int cmd, unsigned long arg) |
| 229 | { |
| 230 | void __user *argp = (void __user *)arg; |
| 231 | int __user *p = argp; |
| 232 | static struct watchdog_info ident = { |
| 233 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, |
| 234 | .firmware_version = 1, |
| 235 | .identity = "WDT Eurotech CPU-1220/1410", |
| 236 | }; |
| 237 | |
| 238 | int time; |
| 239 | int options, retval = -EINVAL; |
| 240 | |
| 241 | switch(cmd) { |
| 242 | default: |
| 243 | return -ENOIOCTLCMD; |
| 244 | |
| 245 | case WDIOC_GETSUPPORT: |
| 246 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; |
| 247 | |
| 248 | case WDIOC_GETSTATUS: |
| 249 | case WDIOC_GETBOOTSTATUS: |
| 250 | return put_user(0, p); |
| 251 | |
| 252 | case WDIOC_KEEPALIVE: |
| 253 | eurwdt_ping(); |
| 254 | return 0; |
| 255 | |
| 256 | case WDIOC_SETTIMEOUT: |
| 257 | if (copy_from_user(&time, p, sizeof(int))) |
| 258 | return -EFAULT; |
| 259 | |
| 260 | /* Sanity check */ |
| 261 | if (time < 0 || time > 255) |
| 262 | return -EINVAL; |
| 263 | |
| 264 | eurwdt_timeout = time; |
| 265 | eurwdt_set_timeout(time); |
| 266 | /* Fall */ |
| 267 | |
| 268 | case WDIOC_GETTIMEOUT: |
| 269 | return put_user(eurwdt_timeout, p); |
| 270 | |
| 271 | case WDIOC_SETOPTIONS: |
| 272 | if (get_user(options, p)) |
| 273 | return -EFAULT; |
| 274 | if (options & WDIOS_DISABLECARD) { |
| 275 | eurwdt_disable_timer(); |
| 276 | retval = 0; |
| 277 | } |
| 278 | if (options & WDIOS_ENABLECARD) { |
| 279 | eurwdt_activate_timer(); |
| 280 | eurwdt_ping(); |
| 281 | retval = 0; |
| 282 | } |
| 283 | return retval; |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | /** |
| 288 | * eurwdt_open: |
| 289 | * @inode: inode of device |
| 290 | * @file: file handle to device |
| 291 | * |
| 292 | * The misc device has been opened. The watchdog device is single |
| 293 | * open and on opening we load the counter. |
| 294 | */ |
| 295 | |
| 296 | static int eurwdt_open(struct inode *inode, struct file *file) |
| 297 | { |
| 298 | if (test_and_set_bit(0, &eurwdt_is_open)) |
| 299 | return -EBUSY; |
| 300 | eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */ |
| 301 | /* Activate the WDT */ |
| 302 | eurwdt_activate_timer(); |
| 303 | return nonseekable_open(inode, file); |
| 304 | } |
| 305 | |
| 306 | /** |
| 307 | * eurwdt_release: |
| 308 | * @inode: inode to board |
| 309 | * @file: file handle to board |
| 310 | * |
| 311 | * The watchdog has a configurable API. There is a religious dispute |
| 312 | * between people who want their watchdog to be able to shut down and |
| 313 | * those who want to be sure if the watchdog manager dies the machine |
| 314 | * reboots. In the former case we disable the counters, in the latter |
| 315 | * case you have to open it again very soon. |
| 316 | */ |
| 317 | |
| 318 | static int eurwdt_release(struct inode *inode, struct file *file) |
| 319 | { |
| 320 | if (eur_expect_close == 42) { |
| 321 | eurwdt_disable_timer(); |
| 322 | } else { |
| 323 | printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n"); |
| 324 | eurwdt_ping(); |
| 325 | } |
| 326 | clear_bit(0, &eurwdt_is_open); |
| 327 | eur_expect_close = 0; |
| 328 | return 0; |
| 329 | } |
| 330 | |
| 331 | /** |
| 332 | * eurwdt_notify_sys: |
| 333 | * @this: our notifier block |
| 334 | * @code: the event being reported |
| 335 | * @unused: unused |
| 336 | * |
| 337 | * Our notifier is called on system shutdowns. We want to turn the card |
| 338 | * off at reboot otherwise the machine will reboot again during memory |
| 339 | * test or worse yet during the following fsck. This would suck, in fact |
| 340 | * trust me - if it happens it does suck. |
| 341 | */ |
| 342 | |
| 343 | static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code, |
| 344 | void *unused) |
| 345 | { |
| 346 | if (code == SYS_DOWN || code == SYS_HALT) { |
| 347 | /* Turn the card off */ |
| 348 | eurwdt_disable_timer(); |
| 349 | } |
| 350 | |
| 351 | return NOTIFY_DONE; |
| 352 | } |
| 353 | |
| 354 | /* |
| 355 | * Kernel Interfaces |
| 356 | */ |
| 357 | |
| 358 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 359 | static const struct file_operations eurwdt_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | .owner = THIS_MODULE, |
| 361 | .llseek = no_llseek, |
| 362 | .write = eurwdt_write, |
| 363 | .ioctl = eurwdt_ioctl, |
| 364 | .open = eurwdt_open, |
| 365 | .release = eurwdt_release, |
| 366 | }; |
| 367 | |
| 368 | static struct miscdevice eurwdt_miscdev = { |
| 369 | .minor = WATCHDOG_MINOR, |
| 370 | .name = "watchdog", |
| 371 | .fops = &eurwdt_fops, |
| 372 | }; |
| 373 | |
| 374 | /* |
| 375 | * The WDT card needs to learn about soft shutdowns in order to |
| 376 | * turn the timebomb registers off. |
| 377 | */ |
| 378 | |
| 379 | static struct notifier_block eurwdt_notifier = { |
| 380 | .notifier_call = eurwdt_notify_sys, |
| 381 | }; |
| 382 | |
| 383 | /** |
| 384 | * cleanup_module: |
| 385 | * |
| 386 | * Unload the watchdog. You cannot do this with any file handles open. |
| 387 | * If your watchdog is set to continue ticking on close and you unload |
| 388 | * it, well it keeps ticking. We won't get the interrupt but the board |
| 389 | * will not touch PC memory so all is fine. You just have to load a new |
| 390 | * module in 60 seconds or reboot. |
| 391 | */ |
| 392 | |
| 393 | static void __exit eurwdt_exit(void) |
| 394 | { |
| 395 | eurwdt_lock_chip(); |
| 396 | |
| 397 | misc_deregister(&eurwdt_miscdev); |
| 398 | |
| 399 | unregister_reboot_notifier(&eurwdt_notifier); |
| 400 | release_region(io, 2); |
| 401 | free_irq(irq, NULL); |
| 402 | } |
| 403 | |
| 404 | /** |
| 405 | * eurwdt_init: |
| 406 | * |
| 407 | * Set up the WDT watchdog board. After grabbing the resources |
| 408 | * we require we need also to unlock the device. |
| 409 | * The open() function will actually kick the board off. |
| 410 | */ |
| 411 | |
| 412 | static int __init eurwdt_init(void) |
| 413 | { |
| 414 | int ret; |
| 415 | |
| 416 | ret = misc_register(&eurwdt_miscdev); |
| 417 | if (ret) { |
| 418 | printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n", |
| 419 | WATCHDOG_MINOR); |
| 420 | goto out; |
| 421 | } |
| 422 | |
Thomas Gleixner | 0f2ed4c | 2006-07-01 19:29:33 -0700 | [diff] [blame] | 423 | ret = request_irq(irq, eurwdt_interrupt, IRQF_DISABLED, "eurwdt", NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | if(ret) { |
| 425 | printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq); |
| 426 | goto outmisc; |
| 427 | } |
| 428 | |
| 429 | if (!request_region(io, 2, "eurwdt")) { |
| 430 | printk(KERN_ERR "eurwdt: IO %X is not free.\n", io); |
| 431 | ret = -EBUSY; |
| 432 | goto outirq; |
| 433 | } |
| 434 | |
| 435 | ret = register_reboot_notifier(&eurwdt_notifier); |
| 436 | if (ret) { |
| 437 | printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret); |
| 438 | goto outreg; |
| 439 | } |
| 440 | |
| 441 | eurwdt_unlock_chip(); |
| 442 | |
| 443 | ret = 0; |
| 444 | printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)" |
| 445 | " - timeout event: %s\n", |
| 446 | io, irq, (!strcmp("int", ev) ? "int" : "reboot")); |
| 447 | |
| 448 | out: |
| 449 | return ret; |
| 450 | |
| 451 | outreg: |
| 452 | release_region(io, 2); |
| 453 | |
| 454 | outirq: |
| 455 | free_irq(irq, NULL); |
| 456 | |
| 457 | outmisc: |
| 458 | misc_deregister(&eurwdt_miscdev); |
| 459 | goto out; |
| 460 | } |
| 461 | |
| 462 | module_init(eurwdt_init); |
| 463 | module_exit(eurwdt_exit); |
| 464 | |
| 465 | MODULE_AUTHOR("Rodolfo Giometti"); |
| 466 | MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog"); |
| 467 | MODULE_LICENSE("GPL"); |
| 468 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |