11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 60xx Single Board Computer Watchdog Timer driver for Linux 2.2.x 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4143a2e54bf53216674eada16e8953f48b159e08aWim Van Sebroeck * Based on acquirewdt.c by Alan Cox. 51da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 61da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This program is free software; you can redistribute it and/or 71da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * modify it under the terms of the GNU General Public License 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * as published by the Free Software Foundation; either version 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2 of the License, or (at your option) any later version. 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The author does NOT admit liability nor provide warranty for 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * any of this software. This material is provided "AS-IS" in 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the hope that it may be useful for others. 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * (c) Copyright 2000 Jakob Oestergaard <jakob@unthought.net> 161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 12/4 - 2000 [Initial revision] 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 25/4 - 2000 Added /dev/watchdog support 191780de41406d783aa57459ba636a09aeda21d180Alan Cox * 09/5 - 2001 [smj@oro.net] fixed fop_write to "return 1" 201780de41406d783aa57459ba636a09aeda21d180Alan Cox * on success 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 12/4 - 2002 [rob@osinvestor.com] eliminate fop_read 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * fix possible wdt_is_open race 231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * add CONFIG_WATCHDOG_NOWAYOUT support 241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * remove lock_kernel/unlock_kernel pairs 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added KERN_* to printk's 261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * got rid of extraneous comments 271780de41406d783aa57459ba636a09aeda21d180Alan Cox * changed watchdog_info to correctly reflect what 281780de41406d783aa57459ba636a09aeda21d180Alan Cox * the driver offers 291780de41406d783aa57459ba636a09aeda21d180Alan Cox * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, 301780de41406d783aa57459ba636a09aeda21d180Alan Cox * WDIOC_SETTIMEOUT, WDIOC_GETTIMEOUT, and 311780de41406d783aa57459ba636a09aeda21d180Alan Cox * WDIOC_SETOPTIONS ioctls 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * use module_param 341780de41406d783aa57459ba636a09aeda21d180Alan Cox * made timeout (the emulated heartbeat) a 351780de41406d783aa57459ba636a09aeda21d180Alan Cox * module_param 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * made the keepalive ping an internal subroutine 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * made wdt_stop and wdt_start module params 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added extra printk's for startup problems 391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added MODULE_AUTHOR and MODULE_DESCRIPTION info 401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This WDT driver is different from the other Linux WDT 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * drivers in the following ways: 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * *) The driver will ping the watchdog by itself, because this 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * particular WDT has a very short timeout (one second) and it 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * would be insane to count on any userspace daemon always 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * getting scheduled within that time frame. 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5127c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 5227c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/module.h> 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/moduleparam.h> 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/types.h> 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/timer.h> 571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/jiffies.h> 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/miscdevice.h> 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/watchdog.h> 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/fs.h> 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/ioport.h> 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/notifier.h> 631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/reboot.h> 641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/init.h> 651780de41406d783aa57459ba636a09aeda21d180Alan Cox#include <linux/io.h> 661780de41406d783aa57459ba636a09aeda21d180Alan Cox#include <linux/uaccess.h> 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define OUR_NAME "sbc60xxwdt" 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define PFX OUR_NAME ": " 711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * You must set these - The driver cannot probe for the settings 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_stop = 0x45; 771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(wdt_stop, int, 0); 781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)"); 791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_start = 0x443; 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(wdt_start, int, 0); 821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)"); 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The 60xx board can use watchdog timeout values from one second 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * to several minutes. The default is one second, so if we reset 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the watchdog every ~250ms we should be safe. 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define WDT_INTERVAL (HZ/4+1) 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * We must not require too good response from the userspace daemon. 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Here we require the userspace daemon to send us a heartbeat 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * char to /dev/watchdog every 30 seconds. 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If the daemon pulses us every 25 seconds, we can still afford 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * a 5 second scheduling delay on the (high priority) daemon. That 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * should be sufficient for a box under any load. 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ 1021780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic int timeout = WATCHDOG_TIMEOUT; /* in seconds, multiplied by HZ to 1031780de41406d783aa57459ba636a09aeda21d180Alan Cox get seconds to wait for a ping */ 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(timeout, int, 0); 1051780de41406d783aa57459ba636a09aeda21d180Alan CoxMODULE_PARM_DESC(timeout, 1061780de41406d783aa57459ba636a09aeda21d180Alan Cox "Watchdog timeout in seconds. (1<=timeout<=3600, default=" 1071780de41406d783aa57459ba636a09aeda21d180Alan Cox __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 10986a1e1896c2710402e29a875d8d830244274244dWim Van Sebroeckstatic bool nowayout = WATCHDOG_NOWAYOUT; 11086a1e1896c2710402e29a875d8d830244274244dWim Van Sebroeckmodule_param(nowayout, bool, 0); 1111780de41406d783aa57459ba636a09aeda21d180Alan CoxMODULE_PARM_DESC(nowayout, 1121780de41406d783aa57459ba636a09aeda21d180Alan Cox "Watchdog cannot be stopped once started (default=" 1131780de41406d783aa57459ba636a09aeda21d180Alan Cox __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 1141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_timer_ping(unsigned long); 11682eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slabystatic DEFINE_TIMER(timer, wdt_timer_ping, 0, 0); 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic unsigned long next_heartbeat; 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic unsigned long wdt_is_open; 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic char wdt_expect_close; 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Whack the dog 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_timer_ping(unsigned long data) 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* If we got a heartbeat pulse within the WDT_US_INTERVAL 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we agree to ping the WDT 1291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1301780de41406d783aa57459ba636a09aeda21d180Alan Cox if (time_before(jiffies, next_heartbeat)) { 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Ping the WDT by reading from wdt_start */ 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds inb_p(wdt_start); 1331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Re-set the timer interval */ 13482eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slaby mod_timer(&timer, jiffies + WDT_INTERVAL); 1351780de41406d783aa57459ba636a09aeda21d180Alan Cox } else 13627c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_warn("Heartbeat lost! Will not ping the watchdog\n"); 1371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Utility routines 1411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_startup(void) 1441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds next_heartbeat = jiffies + (timeout * HZ); 1461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Start the timer */ 14882eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slaby mod_timer(&timer, jiffies + WDT_INTERVAL); 14927c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_info("Watchdog timer is now enabled\n"); 1501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_turnoff(void) 1531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Stop the timer */ 1551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds del_timer(&timer); 1561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds inb_p(wdt_stop); 15727c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_info("Watchdog timer is now disabled...\n"); 1581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_keepalive(void) 1611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* user land ping */ 1631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds next_heartbeat = jiffies + (timeout * HZ); 1641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * /dev/watchdog handling 1681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1701780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic ssize_t fop_write(struct file *file, const char __user *buf, 1711780de41406d783aa57459ba636a09aeda21d180Alan Cox size_t count, loff_t *ppos) 1721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* See if we got the magic character 'V' and reload the timer */ 1741780de41406d783aa57459ba636a09aeda21d180Alan Cox if (count) { 1751780de41406d783aa57459ba636a09aeda21d180Alan Cox if (!nowayout) { 1761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds size_t ofs; 1771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1781780de41406d783aa57459ba636a09aeda21d180Alan Cox /* note: just in case someone wrote the 1791780de41406d783aa57459ba636a09aeda21d180Alan Cox magic character five months ago... */ 1801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 0; 1811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1821780de41406d783aa57459ba636a09aeda21d180Alan Cox /* scan to see whether or not we got the 1831780de41406d783aa57459ba636a09aeda21d180Alan Cox magic character */ 1841780de41406d783aa57459ba636a09aeda21d180Alan Cox for (ofs = 0; ofs != count; ofs++) { 1851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds char c; 1867944d3a5a70ee5c1904ed1e8b1d71ff0af2854d9Wim Van Sebroeck if (get_user(c, buf + ofs)) 1871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EFAULT; 1881780de41406d783aa57459ba636a09aeda21d180Alan Cox if (c == 'V') 1891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 42; 1901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1931780de41406d783aa57459ba636a09aeda21d180Alan Cox /* Well, anyhow someone wrote to us, we should 1941780de41406d783aa57459ba636a09aeda21d180Alan Cox return that favour */ 1951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_keepalive(); 1961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return count; 1981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2001780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic int fop_open(struct inode *inode, struct file *file) 2011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Just in case we're already talking to someone... */ 2031780de41406d783aa57459ba636a09aeda21d180Alan Cox if (test_and_set_bit(0, &wdt_is_open)) 2041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EBUSY; 2051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (nowayout) 2071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __module_get(THIS_MODULE); 2081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Good, fire up the show */ 2101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_startup(); 2116abe78bf195c633f67f6349e3d09b2bcd5d32a79Wim Van Sebroeck return nonseekable_open(inode, file); 2121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2141780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic int fop_close(struct inode *inode, struct file *file) 2151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2161780de41406d783aa57459ba636a09aeda21d180Alan Cox if (wdt_expect_close == 42) 2171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 2181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else { 2191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds del_timer(&timer); 22027c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_crit("device file closed unexpectedly. Will not stop the WDT!\n"); 2211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clear_bit(0, &wdt_is_open); 2231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 0; 2241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 2251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2271780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 2281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds void __user *argp = (void __user *)arg; 2301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int __user *p = argp; 2311780de41406d783aa57459ba636a09aeda21d180Alan Cox static const struct watchdog_info ident = { 2321780de41406d783aa57459ba636a09aeda21d180Alan Cox .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 2331780de41406d783aa57459ba636a09aeda21d180Alan Cox WDIOF_MAGICCLOSE, 2341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .firmware_version = 1, 2351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .identity = "SBC60xx", 2361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds }; 2371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2381780de41406d783aa57459ba636a09aeda21d180Alan Cox switch (cmd) { 2391780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETSUPPORT: 2407944d3a5a70ee5c1904ed1e8b1d71ff0af2854d9Wim Van Sebroeck return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; 2411780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETSTATUS: 2421780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETBOOTSTATUS: 2431780de41406d783aa57459ba636a09aeda21d180Alan Cox return put_user(0, p); 2441780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_SETOPTIONS: 2451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 2461780de41406d783aa57459ba636a09aeda21d180Alan Cox int new_options, retval = -EINVAL; 2471780de41406d783aa57459ba636a09aeda21d180Alan Cox if (get_user(new_options, p)) 2481780de41406d783aa57459ba636a09aeda21d180Alan Cox return -EFAULT; 2491780de41406d783aa57459ba636a09aeda21d180Alan Cox if (new_options & WDIOS_DISABLECARD) { 2501780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_turnoff(); 2511780de41406d783aa57459ba636a09aeda21d180Alan Cox retval = 0; 2521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2531780de41406d783aa57459ba636a09aeda21d180Alan Cox if (new_options & WDIOS_ENABLECARD) { 2541780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_startup(); 2551780de41406d783aa57459ba636a09aeda21d180Alan Cox retval = 0; 2561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2571780de41406d783aa57459ba636a09aeda21d180Alan Cox return retval; 2581780de41406d783aa57459ba636a09aeda21d180Alan Cox } 2590c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck case WDIOC_KEEPALIVE: 2600c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck wdt_keepalive(); 2610c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck return 0; 2621780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_SETTIMEOUT: 2631780de41406d783aa57459ba636a09aeda21d180Alan Cox { 2641780de41406d783aa57459ba636a09aeda21d180Alan Cox int new_timeout; 2651780de41406d783aa57459ba636a09aeda21d180Alan Cox if (get_user(new_timeout, p)) 2661780de41406d783aa57459ba636a09aeda21d180Alan Cox return -EFAULT; 2671780de41406d783aa57459ba636a09aeda21d180Alan Cox /* arbitrary upper limit */ 2681780de41406d783aa57459ba636a09aeda21d180Alan Cox if (new_timeout < 1 || new_timeout > 3600) 2691780de41406d783aa57459ba636a09aeda21d180Alan Cox return -EINVAL; 2701780de41406d783aa57459ba636a09aeda21d180Alan Cox 2711780de41406d783aa57459ba636a09aeda21d180Alan Cox timeout = new_timeout; 2721780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_keepalive(); 2731780de41406d783aa57459ba636a09aeda21d180Alan Cox /* Fall through */ 2741780de41406d783aa57459ba636a09aeda21d180Alan Cox } 2751780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETTIMEOUT: 2761780de41406d783aa57459ba636a09aeda21d180Alan Cox return put_user(timeout, p); 2770c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck default: 2780c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck return -ENOTTY; 2791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 28262322d2554d2f9680c8ace7bbf1f97d8fa84ad1aArjan van de Venstatic const struct file_operations wdt_fops = { 2831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .owner = THIS_MODULE, 2841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .llseek = no_llseek, 2851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .write = fop_write, 2861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .open = fop_open, 2871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .release = fop_close, 2881780de41406d783aa57459ba636a09aeda21d180Alan Cox .unlocked_ioctl = fop_ioctl, 2891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 2901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct miscdevice wdt_miscdev = { 2921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .minor = WATCHDOG_MINOR, 2931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .name = "watchdog", 2941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .fops = &wdt_fops, 2951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 2961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 2981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Notifier for system down 2991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_notify_sys(struct notifier_block *this, unsigned long code, 3021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds void *unused) 3031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3041780de41406d783aa57459ba636a09aeda21d180Alan Cox if (code == SYS_DOWN || code == SYS_HALT) 3051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 3061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return NOTIFY_DONE; 3071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 3101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The WDT needs to learn about soft shutdowns in order to 3111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * turn the timebomb registers off. 3121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3141780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic struct notifier_block wdt_notifier = { 3151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .notifier_call = wdt_notify_sys, 3161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 3171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void __exit sbc60xxwdt_unload(void) 3191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 3211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Deregister */ 3231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds misc_deregister(&wdt_miscdev); 3241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unregister_reboot_notifier(&wdt_notifier); 3261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((wdt_stop != 0x45) && (wdt_stop != wdt_start)) 3271780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_stop, 1); 3281780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_start, 1); 3291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int __init sbc60xxwdt_init(void) 3321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int rc = -EBUSY; 3341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3351780de41406d783aa57459ba636a09aeda21d180Alan Cox if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */ 3361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout = WATCHDOG_TIMEOUT; 33727c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_info("timeout value must be 1 <= x <= 3600, using %d\n", 33827c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches timeout); 3391780de41406d783aa57459ba636a09aeda21d180Alan Cox } 3401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3411780de41406d783aa57459ba636a09aeda21d180Alan Cox if (!request_region(wdt_start, 1, "SBC 60XX WDT")) { 34227c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_err("I/O address 0x%04x already in use\n", wdt_start); 3431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = -EIO; 3441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out; 3451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* We cannot reserve 0x45 - the kernel already has! */ 3481780de41406d783aa57459ba636a09aeda21d180Alan Cox if (wdt_stop != 0x45 && wdt_stop != wdt_start) { 3491780de41406d783aa57459ba636a09aeda21d180Alan Cox if (!request_region(wdt_stop, 1, "SBC 60XX WDT")) { 35027c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_err("I/O address 0x%04x already in use\n", wdt_stop); 3511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = -EIO; 3521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_region1; 3531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 356c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck rc = register_reboot_notifier(&wdt_notifier); 3571780de41406d783aa57459ba636a09aeda21d180Alan Cox if (rc) { 35827c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_err("cannot register reboot notifier (err=%d)\n", rc); 3591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_region2; 3601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 362c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck rc = misc_register(&wdt_miscdev); 3631780de41406d783aa57459ba636a09aeda21d180Alan Cox if (rc) { 36427c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_err("cannot register miscdev on minor=%d (err=%d)\n", 36527c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches wdt_miscdev.minor, rc); 366c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck goto err_out_reboot; 3671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 36827c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches pr_info("WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n", 36927c766aaacb265d625dc634bf7903f7f9fd0c697Joe Perches timeout, nowayout); 3701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 3721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 373c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeckerr_out_reboot: 374c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck unregister_reboot_notifier(&wdt_notifier); 3751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_region2: 3761780de41406d783aa57459ba636a09aeda21d180Alan Cox if (wdt_stop != 0x45 && wdt_stop != wdt_start) 3771780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_stop, 1); 3781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_region1: 3791780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_start, 1); 3801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out: 3811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return rc; 3821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_init(sbc60xxwdt_init); 3851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_exit(sbc60xxwdt_unload); 3861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>"); 3881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver"); 3891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_LICENSE("GPL"); 390