1*2874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 2b7e04f8cSWim Van Sebroeck /* 3b7e04f8cSWim Van Sebroeck * W83877F Computer Watchdog Timer driver 4b7e04f8cSWim Van Sebroeck * 5b7e04f8cSWim Van Sebroeck * Based on acquirewdt.c by Alan Cox, 6b7e04f8cSWim Van Sebroeck * and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net> 7b7e04f8cSWim Van Sebroeck * 8b7e04f8cSWim Van Sebroeck * The authors do NOT admit liability nor provide warranty for 9b7e04f8cSWim Van Sebroeck * any of this software. This material is provided "AS-IS" in 10b7e04f8cSWim Van Sebroeck * the hope that it may be useful for others. 11b7e04f8cSWim Van Sebroeck * 12b7e04f8cSWim Van Sebroeck * (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net> 13b7e04f8cSWim Van Sebroeck * 14b7e04f8cSWim Van Sebroeck * 4/19 - 2001 [Initial revision] 15b7e04f8cSWim Van Sebroeck * 9/27 - 2001 Added spinlocking 16b7e04f8cSWim Van Sebroeck * 4/12 - 2002 [rob@osinvestor.com] Eliminate extra comments 17b7e04f8cSWim Van Sebroeck * Eliminate fop_read 18b7e04f8cSWim Van Sebroeck * Eliminate extra spin_unlock 19b7e04f8cSWim Van Sebroeck * Added KERN_* tags to printks 20b7e04f8cSWim Van Sebroeck * add CONFIG_WATCHDOG_NOWAYOUT support 21b7e04f8cSWim Van Sebroeck * fix possible wdt_is_open race 22c1cfd1a2SAlan Cox * changed watchdog_info to correctly reflect what 23c1cfd1a2SAlan Cox * the driver offers 24c1cfd1a2SAlan Cox * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, 25c1cfd1a2SAlan Cox * WDIOC_SETTIMEOUT, 26b7e04f8cSWim Van Sebroeck * WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls 27b7e04f8cSWim Van Sebroeck * 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces 28b7e04f8cSWim Van Sebroeck * added extra printk's for startup problems 29b7e04f8cSWim Van Sebroeck * use module_param 30c1cfd1a2SAlan Cox * made timeout (the emulated heartbeat) a 31c1cfd1a2SAlan Cox * module_param 32b7e04f8cSWim Van Sebroeck * made the keepalive ping an internal subroutine 33b7e04f8cSWim Van Sebroeck * 34b7e04f8cSWim Van Sebroeck * This WDT driver is different from most other Linux WDT 35b7e04f8cSWim Van Sebroeck * drivers in that the driver will ping the watchdog by itself, 36b7e04f8cSWim Van Sebroeck * because this particular WDT has a very short timeout (1.6 37b7e04f8cSWim Van Sebroeck * seconds) and it would be insane to count on any userspace 38b7e04f8cSWim Van Sebroeck * daemon always getting scheduled within that time frame. 39b7e04f8cSWim Van Sebroeck */ 40b7e04f8cSWim Van Sebroeck 4127c766aaSJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 4227c766aaSJoe Perches 43b7e04f8cSWim Van Sebroeck #include <linux/module.h> 44b7e04f8cSWim Van Sebroeck #include <linux/moduleparam.h> 45b7e04f8cSWim Van Sebroeck #include <linux/types.h> 46b7e04f8cSWim Van Sebroeck #include <linux/timer.h> 47b7e04f8cSWim Van Sebroeck #include <linux/jiffies.h> 48b7e04f8cSWim Van Sebroeck #include <linux/miscdevice.h> 49b7e04f8cSWim Van Sebroeck #include <linux/watchdog.h> 50b7e04f8cSWim Van Sebroeck #include <linux/fs.h> 51b7e04f8cSWim Van Sebroeck #include <linux/ioport.h> 52b7e04f8cSWim Van Sebroeck #include <linux/notifier.h> 53b7e04f8cSWim Van Sebroeck #include <linux/reboot.h> 54b7e04f8cSWim Van Sebroeck #include <linux/init.h> 55c1cfd1a2SAlan Cox #include <linux/io.h> 56c1cfd1a2SAlan Cox #include <linux/uaccess.h> 57b7e04f8cSWim Van Sebroeck 58b7e04f8cSWim Van Sebroeck #define OUR_NAME "w83877f_wdt" 59b7e04f8cSWim Van Sebroeck 60b7e04f8cSWim Van Sebroeck #define ENABLE_W83877F_PORT 0x3F0 61b7e04f8cSWim Van Sebroeck #define ENABLE_W83877F 0x87 62b7e04f8cSWim Van Sebroeck #define DISABLE_W83877F 0xAA 63b7e04f8cSWim Van Sebroeck #define WDT_PING 0x443 64b7e04f8cSWim Van Sebroeck #define WDT_REGISTER 0x14 65b7e04f8cSWim Van Sebroeck #define WDT_ENABLE 0x9C 66b7e04f8cSWim Van Sebroeck #define WDT_DISABLE 0x8C 67b7e04f8cSWim Van Sebroeck 68b7e04f8cSWim Van Sebroeck /* 69b7e04f8cSWim Van Sebroeck * The W83877F seems to be fixed at 1.6s timeout (at least on the 70b7e04f8cSWim Van Sebroeck * EMACS PC-104 board I'm using). If we reset the watchdog every 71b7e04f8cSWim Van Sebroeck * ~250ms we should be safe. */ 72b7e04f8cSWim Van Sebroeck 73b7e04f8cSWim Van Sebroeck #define WDT_INTERVAL (HZ/4+1) 74b7e04f8cSWim Van Sebroeck 75b7e04f8cSWim Van Sebroeck /* 76b7e04f8cSWim Van Sebroeck * We must not require too good response from the userspace daemon. 77b7e04f8cSWim Van Sebroeck * Here we require the userspace daemon to send us a heartbeat 78b7e04f8cSWim Van Sebroeck * char to /dev/watchdog every 30 seconds. 79b7e04f8cSWim Van Sebroeck */ 80b7e04f8cSWim Van Sebroeck 81b7e04f8cSWim Van Sebroeck #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ 82c1cfd1a2SAlan Cox /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ 83c1cfd1a2SAlan Cox static int timeout = WATCHDOG_TIMEOUT; 84b7e04f8cSWim Van Sebroeck module_param(timeout, int, 0); 85c1cfd1a2SAlan Cox MODULE_PARM_DESC(timeout, 86c1cfd1a2SAlan Cox "Watchdog timeout in seconds. (1<=timeout<=3600, default=" 87c1cfd1a2SAlan Cox __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); 88b7e04f8cSWim Van Sebroeck 89b7e04f8cSWim Van Sebroeck 9086a1e189SWim Van Sebroeck static bool nowayout = WATCHDOG_NOWAYOUT; 9186a1e189SWim Van Sebroeck module_param(nowayout, bool, 0); 92c1cfd1a2SAlan Cox MODULE_PARM_DESC(nowayout, 93c1cfd1a2SAlan Cox "Watchdog cannot be stopped once started (default=" 94c1cfd1a2SAlan Cox __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 95b7e04f8cSWim Van Sebroeck 9624ed960aSKees Cook static void wdt_timer_ping(struct timer_list *); 971d27e3e2SKees Cook static DEFINE_TIMER(timer, wdt_timer_ping); 98b7e04f8cSWim Van Sebroeck static unsigned long next_heartbeat; 99b7e04f8cSWim Van Sebroeck static unsigned long wdt_is_open; 100b7e04f8cSWim Van Sebroeck static char wdt_expect_close; 101c7dfd0ccSAlexey Dobriyan static DEFINE_SPINLOCK(wdt_spinlock); 102b7e04f8cSWim Van Sebroeck 103b7e04f8cSWim Van Sebroeck /* 104b7e04f8cSWim Van Sebroeck * Whack the dog 105b7e04f8cSWim Van Sebroeck */ 106b7e04f8cSWim Van Sebroeck 10724ed960aSKees Cook static void wdt_timer_ping(struct timer_list *unused) 108b7e04f8cSWim Van Sebroeck { 109b7e04f8cSWim Van Sebroeck /* If we got a heartbeat pulse within the WDT_US_INTERVAL 110b7e04f8cSWim Van Sebroeck * we agree to ping the WDT 111b7e04f8cSWim Van Sebroeck */ 112c1cfd1a2SAlan Cox if (time_before(jiffies, next_heartbeat)) { 113b7e04f8cSWim Van Sebroeck /* Ping the WDT */ 114b7e04f8cSWim Van Sebroeck spin_lock(&wdt_spinlock); 115b7e04f8cSWim Van Sebroeck 116b7e04f8cSWim Van Sebroeck /* Ping the WDT by reading from WDT_PING */ 117b7e04f8cSWim Van Sebroeck inb_p(WDT_PING); 118b7e04f8cSWim Van Sebroeck 119b7e04f8cSWim Van Sebroeck /* Re-set the timer interval */ 120b7e04f8cSWim Van Sebroeck mod_timer(&timer, jiffies + WDT_INTERVAL); 121b7e04f8cSWim Van Sebroeck 122b7e04f8cSWim Van Sebroeck spin_unlock(&wdt_spinlock); 123b7e04f8cSWim Van Sebroeck 124c1cfd1a2SAlan Cox } else 12527c766aaSJoe Perches pr_warn("Heartbeat lost! Will not ping the watchdog\n"); 126b7e04f8cSWim Van Sebroeck } 127b7e04f8cSWim Van Sebroeck 128b7e04f8cSWim Van Sebroeck /* 129b7e04f8cSWim Van Sebroeck * Utility routines 130b7e04f8cSWim Van Sebroeck */ 131b7e04f8cSWim Van Sebroeck 132b7e04f8cSWim Van Sebroeck static void wdt_change(int writeval) 133b7e04f8cSWim Van Sebroeck { 134b7e04f8cSWim Van Sebroeck unsigned long flags; 135b7e04f8cSWim Van Sebroeck spin_lock_irqsave(&wdt_spinlock, flags); 136b7e04f8cSWim Van Sebroeck 137b7e04f8cSWim Van Sebroeck /* buy some time */ 138b7e04f8cSWim Van Sebroeck inb_p(WDT_PING); 139b7e04f8cSWim Van Sebroeck 140b7e04f8cSWim Van Sebroeck /* make W83877F available */ 141b7e04f8cSWim Van Sebroeck outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT); 142b7e04f8cSWim Van Sebroeck outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT); 143b7e04f8cSWim Van Sebroeck 144b7e04f8cSWim Van Sebroeck /* enable watchdog */ 145b7e04f8cSWim Van Sebroeck outb_p(WDT_REGISTER, ENABLE_W83877F_PORT); 146b7e04f8cSWim Van Sebroeck outb_p(writeval, ENABLE_W83877F_PORT+1); 147b7e04f8cSWim Van Sebroeck 148b7e04f8cSWim Van Sebroeck /* lock the W8387FF away */ 149b7e04f8cSWim Van Sebroeck outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT); 150b7e04f8cSWim Van Sebroeck 151b7e04f8cSWim Van Sebroeck spin_unlock_irqrestore(&wdt_spinlock, flags); 152b7e04f8cSWim Van Sebroeck } 153b7e04f8cSWim Van Sebroeck 154b7e04f8cSWim Van Sebroeck static void wdt_startup(void) 155b7e04f8cSWim Van Sebroeck { 156b7e04f8cSWim Van Sebroeck next_heartbeat = jiffies + (timeout * HZ); 157b7e04f8cSWim Van Sebroeck 158b7e04f8cSWim Van Sebroeck /* Start the timer */ 159b7e04f8cSWim Van Sebroeck mod_timer(&timer, jiffies + WDT_INTERVAL); 160b7e04f8cSWim Van Sebroeck 161b7e04f8cSWim Van Sebroeck wdt_change(WDT_ENABLE); 162b7e04f8cSWim Van Sebroeck 16327c766aaSJoe Perches pr_info("Watchdog timer is now enabled\n"); 164b7e04f8cSWim Van Sebroeck } 165b7e04f8cSWim Van Sebroeck 166b7e04f8cSWim Van Sebroeck static void wdt_turnoff(void) 167b7e04f8cSWim Van Sebroeck { 168b7e04f8cSWim Van Sebroeck /* Stop the timer */ 169b7e04f8cSWim Van Sebroeck del_timer(&timer); 170b7e04f8cSWim Van Sebroeck 171b7e04f8cSWim Van Sebroeck wdt_change(WDT_DISABLE); 172b7e04f8cSWim Van Sebroeck 17327c766aaSJoe Perches pr_info("Watchdog timer is now disabled...\n"); 174b7e04f8cSWim Van Sebroeck } 175b7e04f8cSWim Van Sebroeck 176b7e04f8cSWim Van Sebroeck static void wdt_keepalive(void) 177b7e04f8cSWim Van Sebroeck { 178b7e04f8cSWim Van Sebroeck /* user land ping */ 179b7e04f8cSWim Van Sebroeck next_heartbeat = jiffies + (timeout * HZ); 180b7e04f8cSWim Van Sebroeck } 181b7e04f8cSWim Van Sebroeck 182b7e04f8cSWim Van Sebroeck /* 183b7e04f8cSWim Van Sebroeck * /dev/watchdog handling 184b7e04f8cSWim Van Sebroeck */ 185b7e04f8cSWim Van Sebroeck 186c1cfd1a2SAlan Cox static ssize_t fop_write(struct file *file, const char __user *buf, 187c1cfd1a2SAlan Cox size_t count, loff_t *ppos) 188b7e04f8cSWim Van Sebroeck { 189b7e04f8cSWim Van Sebroeck /* See if we got the magic character 'V' and reload the timer */ 190c1cfd1a2SAlan Cox if (count) { 191c1cfd1a2SAlan Cox if (!nowayout) { 192b7e04f8cSWim Van Sebroeck size_t ofs; 193b7e04f8cSWim Van Sebroeck 194c1cfd1a2SAlan Cox /* note: just in case someone wrote the magic 195c1cfd1a2SAlan Cox character five months ago... */ 196b7e04f8cSWim Van Sebroeck wdt_expect_close = 0; 197b7e04f8cSWim Van Sebroeck 198c1cfd1a2SAlan Cox /* scan to see whether or not we got the 199c1cfd1a2SAlan Cox magic character */ 200c1cfd1a2SAlan Cox for (ofs = 0; ofs != count; ofs++) { 201b7e04f8cSWim Van Sebroeck char c; 202b7e04f8cSWim Van Sebroeck if (get_user(c, buf + ofs)) 203b7e04f8cSWim Van Sebroeck return -EFAULT; 204b7e04f8cSWim Van Sebroeck if (c == 'V') 205b7e04f8cSWim Van Sebroeck wdt_expect_close = 42; 206b7e04f8cSWim Van Sebroeck } 207b7e04f8cSWim Van Sebroeck } 208b7e04f8cSWim Van Sebroeck 209b7e04f8cSWim Van Sebroeck /* someone wrote to us, we should restart timer */ 210b7e04f8cSWim Van Sebroeck wdt_keepalive(); 211b7e04f8cSWim Van Sebroeck } 212b7e04f8cSWim Van Sebroeck return count; 213b7e04f8cSWim Van Sebroeck } 214b7e04f8cSWim Van Sebroeck 215b7e04f8cSWim Van Sebroeck static int fop_open(struct inode *inode, struct file *file) 216b7e04f8cSWim Van Sebroeck { 217b7e04f8cSWim Van Sebroeck /* Just in case we're already talking to someone... */ 218b7e04f8cSWim Van Sebroeck if (test_and_set_bit(0, &wdt_is_open)) 219b7e04f8cSWim Van Sebroeck return -EBUSY; 220b7e04f8cSWim Van Sebroeck 221b7e04f8cSWim Van Sebroeck /* Good, fire up the show */ 222b7e04f8cSWim Van Sebroeck wdt_startup(); 223c5bf68feSKirill Smelkov return stream_open(inode, file); 224b7e04f8cSWim Van Sebroeck } 225b7e04f8cSWim Van Sebroeck 226b7e04f8cSWim Van Sebroeck static int fop_close(struct inode *inode, struct file *file) 227b7e04f8cSWim Van Sebroeck { 228b7e04f8cSWim Van Sebroeck if (wdt_expect_close == 42) 229b7e04f8cSWim Van Sebroeck wdt_turnoff(); 230b7e04f8cSWim Van Sebroeck else { 231b7e04f8cSWim Van Sebroeck del_timer(&timer); 23227c766aaSJoe Perches pr_crit("device file closed unexpectedly. Will not stop the WDT!\n"); 233b7e04f8cSWim Van Sebroeck } 234b7e04f8cSWim Van Sebroeck clear_bit(0, &wdt_is_open); 235b7e04f8cSWim Van Sebroeck wdt_expect_close = 0; 236b7e04f8cSWim Van Sebroeck return 0; 237b7e04f8cSWim Van Sebroeck } 238b7e04f8cSWim Van Sebroeck 239c1cfd1a2SAlan Cox static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 240b7e04f8cSWim Van Sebroeck { 241b7e04f8cSWim Van Sebroeck void __user *argp = (void __user *)arg; 242b7e04f8cSWim Van Sebroeck int __user *p = argp; 243c1cfd1a2SAlan Cox static const struct watchdog_info ident = { 244c1cfd1a2SAlan Cox .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT 245c1cfd1a2SAlan Cox | WDIOF_MAGICCLOSE, 246b7e04f8cSWim Van Sebroeck .firmware_version = 1, 247b7e04f8cSWim Van Sebroeck .identity = "W83877F", 248b7e04f8cSWim Van Sebroeck }; 249b7e04f8cSWim Van Sebroeck 250c1cfd1a2SAlan Cox switch (cmd) { 251b7e04f8cSWim Van Sebroeck case WDIOC_GETSUPPORT: 252b7e04f8cSWim Van Sebroeck return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; 253b7e04f8cSWim Van Sebroeck case WDIOC_GETSTATUS: 254b7e04f8cSWim Van Sebroeck case WDIOC_GETBOOTSTATUS: 255b7e04f8cSWim Van Sebroeck return put_user(0, p); 256b7e04f8cSWim Van Sebroeck case WDIOC_SETOPTIONS: 257b7e04f8cSWim Van Sebroeck { 258b7e04f8cSWim Van Sebroeck int new_options, retval = -EINVAL; 259b7e04f8cSWim Van Sebroeck 260b7e04f8cSWim Van Sebroeck if (get_user(new_options, p)) 261b7e04f8cSWim Van Sebroeck return -EFAULT; 262b7e04f8cSWim Van Sebroeck 263b7e04f8cSWim Van Sebroeck if (new_options & WDIOS_DISABLECARD) { 264b7e04f8cSWim Van Sebroeck wdt_turnoff(); 265b7e04f8cSWim Van Sebroeck retval = 0; 266b7e04f8cSWim Van Sebroeck } 267b7e04f8cSWim Van Sebroeck 268b7e04f8cSWim Van Sebroeck if (new_options & WDIOS_ENABLECARD) { 269b7e04f8cSWim Van Sebroeck wdt_startup(); 270b7e04f8cSWim Van Sebroeck retval = 0; 271b7e04f8cSWim Van Sebroeck } 272b7e04f8cSWim Van Sebroeck 273b7e04f8cSWim Van Sebroeck return retval; 274b7e04f8cSWim Van Sebroeck } 2750c06090cSWim Van Sebroeck case WDIOC_KEEPALIVE: 2760c06090cSWim Van Sebroeck wdt_keepalive(); 2770c06090cSWim Van Sebroeck return 0; 278b7e04f8cSWim Van Sebroeck case WDIOC_SETTIMEOUT: 279b7e04f8cSWim Van Sebroeck { 280b7e04f8cSWim Van Sebroeck int new_timeout; 281b7e04f8cSWim Van Sebroeck 282b7e04f8cSWim Van Sebroeck if (get_user(new_timeout, p)) 283b7e04f8cSWim Van Sebroeck return -EFAULT; 284b7e04f8cSWim Van Sebroeck 285c1cfd1a2SAlan Cox /* arbitrary upper limit */ 286c1cfd1a2SAlan Cox if (new_timeout < 1 || new_timeout > 3600) 287b7e04f8cSWim Van Sebroeck return -EINVAL; 288b7e04f8cSWim Van Sebroeck 289b7e04f8cSWim Van Sebroeck timeout = new_timeout; 290b7e04f8cSWim Van Sebroeck wdt_keepalive(); 291b7e04f8cSWim Van Sebroeck } 292458c8961SGustavo A. R. Silva /* Fall through */ 293b7e04f8cSWim Van Sebroeck case WDIOC_GETTIMEOUT: 294b7e04f8cSWim Van Sebroeck return put_user(timeout, p); 2950c06090cSWim Van Sebroeck default: 2960c06090cSWim Van Sebroeck return -ENOTTY; 297b7e04f8cSWim Van Sebroeck } 298b7e04f8cSWim Van Sebroeck } 299b7e04f8cSWim Van Sebroeck 300b7e04f8cSWim Van Sebroeck static const struct file_operations wdt_fops = { 301b7e04f8cSWim Van Sebroeck .owner = THIS_MODULE, 302b7e04f8cSWim Van Sebroeck .llseek = no_llseek, 303b7e04f8cSWim Van Sebroeck .write = fop_write, 304b7e04f8cSWim Van Sebroeck .open = fop_open, 305b7e04f8cSWim Van Sebroeck .release = fop_close, 306c1cfd1a2SAlan Cox .unlocked_ioctl = fop_ioctl, 307b7e04f8cSWim Van Sebroeck }; 308b7e04f8cSWim Van Sebroeck 309b7e04f8cSWim Van Sebroeck static struct miscdevice wdt_miscdev = { 310b7e04f8cSWim Van Sebroeck .minor = WATCHDOG_MINOR, 311b7e04f8cSWim Van Sebroeck .name = "watchdog", 312b7e04f8cSWim Van Sebroeck .fops = &wdt_fops, 313b7e04f8cSWim Van Sebroeck }; 314b7e04f8cSWim Van Sebroeck 315b7e04f8cSWim Van Sebroeck /* 316b7e04f8cSWim Van Sebroeck * Notifier for system down 317b7e04f8cSWim Van Sebroeck */ 318b7e04f8cSWim Van Sebroeck 319b7e04f8cSWim Van Sebroeck static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 320b7e04f8cSWim Van Sebroeck void *unused) 321b7e04f8cSWim Van Sebroeck { 322b7e04f8cSWim Van Sebroeck if (code == SYS_DOWN || code == SYS_HALT) 323b7e04f8cSWim Van Sebroeck wdt_turnoff(); 324b7e04f8cSWim Van Sebroeck return NOTIFY_DONE; 325b7e04f8cSWim Van Sebroeck } 326b7e04f8cSWim Van Sebroeck 327b7e04f8cSWim Van Sebroeck /* 328b7e04f8cSWim Van Sebroeck * The WDT needs to learn about soft shutdowns in order to 329b7e04f8cSWim Van Sebroeck * turn the timebomb registers off. 330b7e04f8cSWim Van Sebroeck */ 331b7e04f8cSWim Van Sebroeck 332c1cfd1a2SAlan Cox static struct notifier_block wdt_notifier = { 333b7e04f8cSWim Van Sebroeck .notifier_call = wdt_notify_sys, 334b7e04f8cSWim Van Sebroeck }; 335b7e04f8cSWim Van Sebroeck 336b7e04f8cSWim Van Sebroeck static void __exit w83877f_wdt_unload(void) 337b7e04f8cSWim Van Sebroeck { 338b7e04f8cSWim Van Sebroeck wdt_turnoff(); 339b7e04f8cSWim Van Sebroeck 340b7e04f8cSWim Van Sebroeck /* Deregister */ 341b7e04f8cSWim Van Sebroeck misc_deregister(&wdt_miscdev); 342b7e04f8cSWim Van Sebroeck 343b7e04f8cSWim Van Sebroeck unregister_reboot_notifier(&wdt_notifier); 344b7e04f8cSWim Van Sebroeck release_region(WDT_PING, 1); 345b7e04f8cSWim Van Sebroeck release_region(ENABLE_W83877F_PORT, 2); 346b7e04f8cSWim Van Sebroeck } 347b7e04f8cSWim Van Sebroeck 348b7e04f8cSWim Van Sebroeck static int __init w83877f_wdt_init(void) 349b7e04f8cSWim Van Sebroeck { 350b7e04f8cSWim Van Sebroeck int rc = -EBUSY; 351b7e04f8cSWim Van Sebroeck 352c1cfd1a2SAlan Cox if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */ 353b7e04f8cSWim Van Sebroeck timeout = WATCHDOG_TIMEOUT; 35427c766aaSJoe Perches pr_info("timeout value must be 1 <= x <= 3600, using %d\n", 355b7e04f8cSWim Van Sebroeck timeout); 356b7e04f8cSWim Van Sebroeck } 357b7e04f8cSWim Van Sebroeck 358c1cfd1a2SAlan Cox if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) { 35927c766aaSJoe Perches pr_err("I/O address 0x%04x already in use\n", 360b7e04f8cSWim Van Sebroeck ENABLE_W83877F_PORT); 361b7e04f8cSWim Van Sebroeck rc = -EIO; 362b7e04f8cSWim Van Sebroeck goto err_out; 363b7e04f8cSWim Van Sebroeck } 364b7e04f8cSWim Van Sebroeck 365c1cfd1a2SAlan Cox if (!request_region(WDT_PING, 1, "W8387FF WDT")) { 36627c766aaSJoe Perches pr_err("I/O address 0x%04x already in use\n", WDT_PING); 367b7e04f8cSWim Van Sebroeck rc = -EIO; 368b7e04f8cSWim Van Sebroeck goto err_out_region1; 369b7e04f8cSWim Van Sebroeck } 370b7e04f8cSWim Van Sebroeck 371b7e04f8cSWim Van Sebroeck rc = register_reboot_notifier(&wdt_notifier); 372c1cfd1a2SAlan Cox if (rc) { 37327c766aaSJoe Perches pr_err("cannot register reboot notifier (err=%d)\n", rc); 374c6cb13aeSWim Van Sebroeck goto err_out_region2; 375c6cb13aeSWim Van Sebroeck } 376c6cb13aeSWim Van Sebroeck 377c6cb13aeSWim Van Sebroeck rc = misc_register(&wdt_miscdev); 378c1cfd1a2SAlan Cox if (rc) { 37927c766aaSJoe Perches pr_err("cannot register miscdev on minor=%d (err=%d)\n", 380c6cb13aeSWim Van Sebroeck wdt_miscdev.minor, rc); 381c6cb13aeSWim Van Sebroeck goto err_out_reboot; 382b7e04f8cSWim Van Sebroeck } 383b7e04f8cSWim Van Sebroeck 38427c766aaSJoe Perches pr_info("WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n", 385b7e04f8cSWim Van Sebroeck timeout, nowayout); 386b7e04f8cSWim Van Sebroeck 387b7e04f8cSWim Van Sebroeck return 0; 388b7e04f8cSWim Van Sebroeck 389c6cb13aeSWim Van Sebroeck err_out_reboot: 390c6cb13aeSWim Van Sebroeck unregister_reboot_notifier(&wdt_notifier); 391b7e04f8cSWim Van Sebroeck err_out_region2: 392b7e04f8cSWim Van Sebroeck release_region(WDT_PING, 1); 393b7e04f8cSWim Van Sebroeck err_out_region1: 394b7e04f8cSWim Van Sebroeck release_region(ENABLE_W83877F_PORT, 2); 395b7e04f8cSWim Van Sebroeck err_out: 396b7e04f8cSWim Van Sebroeck return rc; 397b7e04f8cSWim Van Sebroeck } 398b7e04f8cSWim Van Sebroeck 399b7e04f8cSWim Van Sebroeck module_init(w83877f_wdt_init); 400b7e04f8cSWim Van Sebroeck module_exit(w83877f_wdt_unload); 401b7e04f8cSWim Van Sebroeck 402b7e04f8cSWim Van Sebroeck MODULE_AUTHOR("Scott and Bill Jennings"); 403b7e04f8cSWim Van Sebroeck MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip"); 404b7e04f8cSWim Van Sebroeck MODULE_LICENSE("GPL"); 405