sbc60xxwdt.c revision 0c06090c9472db0525cb6fe229c3bea33bbbbb3c
11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 60xx Single Board Computer Watchdog Timer driver for Linux 2.2.x 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 41da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 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 511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/module.h> 521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/moduleparam.h> 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/types.h> 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/timer.h> 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/jiffies.h> 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/miscdevice.h> 571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/watchdog.h> 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/fs.h> 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/ioport.h> 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/notifier.h> 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/reboot.h> 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/init.h> 631780de41406d783aa57459ba636a09aeda21d180Alan Cox#include <linux/io.h> 641780de41406d783aa57459ba636a09aeda21d180Alan Cox#include <linux/uaccess.h> 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <asm/system.h> 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define OUR_NAME "sbc60xxwdt" 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define PFX OUR_NAME ": " 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * You must set these - The driver cannot probe for the settings 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_stop = 0x45; 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(wdt_stop, int, 0); 771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)"); 781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_start = 0x443; 801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(wdt_start, int, 0); 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)"); 821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The 60xx board can use watchdog timeout values from one second 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * to several minutes. The default is one second, so if we reset 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the watchdog every ~250ms we should be safe. 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define WDT_INTERVAL (HZ/4+1) 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * We must not require too good response from the userspace daemon. 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Here we require the userspace daemon to send us a heartbeat 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * char to /dev/watchdog every 30 seconds. 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If the daemon pulses us every 25 seconds, we can still afford 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * a 5 second scheduling delay on the (high priority) daemon. That 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * should be sufficient for a box under any load. 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ 1011780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic int timeout = WATCHDOG_TIMEOUT; /* in seconds, multiplied by HZ to 1021780de41406d783aa57459ba636a09aeda21d180Alan Cox get seconds to wait for a ping */ 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(timeout, int, 0); 1041780de41406d783aa57459ba636a09aeda21d180Alan CoxMODULE_PARM_DESC(timeout, 1051780de41406d783aa57459ba636a09aeda21d180Alan Cox "Watchdog timeout in seconds. (1<=timeout<=3600, default=" 1061780de41406d783aa57459ba636a09aeda21d180Alan Cox __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); 1071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1084bfdf37830111321e2cd1fe0102dd776ce93194dAndrey Paninstatic int nowayout = WATCHDOG_NOWAYOUT; 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(nowayout, int, 0); 1101780de41406d783aa57459ba636a09aeda21d180Alan CoxMODULE_PARM_DESC(nowayout, 1111780de41406d783aa57459ba636a09aeda21d180Alan Cox "Watchdog cannot be stopped once started (default=" 1121780de41406d783aa57459ba636a09aeda21d180Alan Cox __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 1131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_timer_ping(unsigned long); 11582eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slabystatic DEFINE_TIMER(timer, wdt_timer_ping, 0, 0); 1161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic unsigned long next_heartbeat; 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic unsigned long wdt_is_open; 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic char wdt_expect_close; 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Whack the dog 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_timer_ping(unsigned long data) 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* If we got a heartbeat pulse within the WDT_US_INTERVAL 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we agree to ping the WDT 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1291780de41406d783aa57459ba636a09aeda21d180Alan Cox if (time_before(jiffies, next_heartbeat)) { 1301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Ping the WDT by reading from wdt_start */ 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds inb_p(wdt_start); 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Re-set the timer interval */ 13382eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slaby mod_timer(&timer, jiffies + WDT_INTERVAL); 1341780de41406d783aa57459ba636a09aeda21d180Alan Cox } else 1351780de41406d783aa57459ba636a09aeda21d180Alan Cox printk(KERN_WARNING PFX 1361780de41406d783aa57459ba636a09aeda21d180Alan Cox "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); 1491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "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); 1571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "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; 1861780de41406d783aa57459ba636a09aeda21d180Alan Cox 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); 2201780de41406d783aa57459ba636a09aeda21d180Alan Cox printk(KERN_CRIT PFX 2211780de41406d783aa57459ba636a09aeda21d180Alan Cox "device file closed unexpectedly. Will not stop the WDT!\n"); 2221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clear_bit(0, &wdt_is_open); 2241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 0; 2251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 2261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2281780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 2291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds void __user *argp = (void __user *)arg; 2311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int __user *p = argp; 2321780de41406d783aa57459ba636a09aeda21d180Alan Cox static const struct watchdog_info ident = { 2331780de41406d783aa57459ba636a09aeda21d180Alan Cox .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 2341780de41406d783aa57459ba636a09aeda21d180Alan Cox WDIOF_MAGICCLOSE, 2351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .firmware_version = 1, 2361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .identity = "SBC60xx", 2371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds }; 2381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2391780de41406d783aa57459ba636a09aeda21d180Alan Cox switch (cmd) { 2401780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETSUPPORT: 2411780de41406d783aa57459ba636a09aeda21d180Alan Cox return copy_to_user(argp, &ident, sizeof(ident))? -EFAULT : 0; 2421780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETSTATUS: 2431780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETBOOTSTATUS: 2441780de41406d783aa57459ba636a09aeda21d180Alan Cox return put_user(0, p); 2451780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_SETOPTIONS: 2461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 2471780de41406d783aa57459ba636a09aeda21d180Alan Cox int new_options, retval = -EINVAL; 2481780de41406d783aa57459ba636a09aeda21d180Alan Cox if (get_user(new_options, p)) 2491780de41406d783aa57459ba636a09aeda21d180Alan Cox return -EFAULT; 2501780de41406d783aa57459ba636a09aeda21d180Alan Cox if (new_options & WDIOS_DISABLECARD) { 2511780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_turnoff(); 2521780de41406d783aa57459ba636a09aeda21d180Alan Cox retval = 0; 2531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2541780de41406d783aa57459ba636a09aeda21d180Alan Cox if (new_options & WDIOS_ENABLECARD) { 2551780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_startup(); 2561780de41406d783aa57459ba636a09aeda21d180Alan Cox retval = 0; 2571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2581780de41406d783aa57459ba636a09aeda21d180Alan Cox return retval; 2591780de41406d783aa57459ba636a09aeda21d180Alan Cox } 2600c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck case WDIOC_KEEPALIVE: 2610c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck wdt_keepalive(); 2620c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck return 0; 2631780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_SETTIMEOUT: 2641780de41406d783aa57459ba636a09aeda21d180Alan Cox { 2651780de41406d783aa57459ba636a09aeda21d180Alan Cox int new_timeout; 2661780de41406d783aa57459ba636a09aeda21d180Alan Cox if (get_user(new_timeout, p)) 2671780de41406d783aa57459ba636a09aeda21d180Alan Cox return -EFAULT; 2681780de41406d783aa57459ba636a09aeda21d180Alan Cox /* arbitrary upper limit */ 2691780de41406d783aa57459ba636a09aeda21d180Alan Cox if (new_timeout < 1 || new_timeout > 3600) 2701780de41406d783aa57459ba636a09aeda21d180Alan Cox return -EINVAL; 2711780de41406d783aa57459ba636a09aeda21d180Alan Cox 2721780de41406d783aa57459ba636a09aeda21d180Alan Cox timeout = new_timeout; 2731780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_keepalive(); 2741780de41406d783aa57459ba636a09aeda21d180Alan Cox /* Fall through */ 2751780de41406d783aa57459ba636a09aeda21d180Alan Cox } 2761780de41406d783aa57459ba636a09aeda21d180Alan Cox case WDIOC_GETTIMEOUT: 2771780de41406d783aa57459ba636a09aeda21d180Alan Cox return put_user(timeout, p); 2780c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck default: 2790c06090c9472db0525cb6fe229c3bea33bbbbb3cWim Van Sebroeck return -ENOTTY; 2801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 28362322d2554d2f9680c8ace7bbf1f97d8fa84ad1aArjan van de Venstatic const struct file_operations wdt_fops = { 2841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .owner = THIS_MODULE, 2851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .llseek = no_llseek, 2861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .write = fop_write, 2871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .open = fop_open, 2881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .release = fop_close, 2891780de41406d783aa57459ba636a09aeda21d180Alan Cox .unlocked_ioctl = fop_ioctl, 2901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 2911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct miscdevice wdt_miscdev = { 2931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .minor = WATCHDOG_MINOR, 2941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .name = "watchdog", 2951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .fops = &wdt_fops, 2961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 2971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 2991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Notifier for system down 3001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_notify_sys(struct notifier_block *this, unsigned long code, 3031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds void *unused) 3041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3051780de41406d783aa57459ba636a09aeda21d180Alan Cox if (code == SYS_DOWN || code == SYS_HALT) 3061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 3071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return NOTIFY_DONE; 3081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 3111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The WDT needs to learn about soft shutdowns in order to 3121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * turn the timebomb registers off. 3131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3151780de41406d783aa57459ba636a09aeda21d180Alan Coxstatic struct notifier_block wdt_notifier = { 3161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .notifier_call = wdt_notify_sys, 3171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 3181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void __exit sbc60xxwdt_unload(void) 3201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 3221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Deregister */ 3241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds misc_deregister(&wdt_miscdev); 3251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unregister_reboot_notifier(&wdt_notifier); 3271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((wdt_stop != 0x45) && (wdt_stop != wdt_start)) 3281780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_stop, 1); 3291780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_start, 1); 3301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int __init sbc60xxwdt_init(void) 3331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int rc = -EBUSY; 3351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3361780de41406d783aa57459ba636a09aeda21d180Alan Cox if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */ 3371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout = WATCHDOG_TIMEOUT; 3381780de41406d783aa57459ba636a09aeda21d180Alan Cox printk(KERN_INFO PFX 3391780de41406d783aa57459ba636a09aeda21d180Alan Cox "timeout value must be 1 <= x <= 3600, using %d\n", 3401780de41406d783aa57459ba636a09aeda21d180Alan Cox timeout); 3411780de41406d783aa57459ba636a09aeda21d180Alan Cox } 3421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3431780de41406d783aa57459ba636a09aeda21d180Alan Cox if (!request_region(wdt_start, 1, "SBC 60XX WDT")) { 3441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 3451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_start); 3461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = -EIO; 3471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out; 3481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* We cannot reserve 0x45 - the kernel already has! */ 3511780de41406d783aa57459ba636a09aeda21d180Alan Cox if (wdt_stop != 0x45 && wdt_stop != wdt_start) { 3521780de41406d783aa57459ba636a09aeda21d180Alan Cox if (!request_region(wdt_stop, 1, "SBC 60XX WDT")) { 3531780de41406d783aa57459ba636a09aeda21d180Alan Cox printk(KERN_ERR PFX 3541780de41406d783aa57459ba636a09aeda21d180Alan Cox "I/O address 0x%04x already in use\n", 3551780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_stop); 3561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = -EIO; 3571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_region1; 3581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 361c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck rc = register_reboot_notifier(&wdt_notifier); 3621780de41406d783aa57459ba636a09aeda21d180Alan Cox if (rc) { 3631780de41406d783aa57459ba636a09aeda21d180Alan Cox printk(KERN_ERR PFX 3641780de41406d783aa57459ba636a09aeda21d180Alan Cox "cannot register reboot notifier (err=%d)\n", rc); 3651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_region2; 3661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 368c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck rc = misc_register(&wdt_miscdev); 3691780de41406d783aa57459ba636a09aeda21d180Alan Cox if (rc) { 3701780de41406d783aa57459ba636a09aeda21d180Alan Cox printk(KERN_ERR PFX 3711780de41406d783aa57459ba636a09aeda21d180Alan Cox "cannot register miscdev on minor=%d (err=%d)\n", 3721780de41406d783aa57459ba636a09aeda21d180Alan Cox wdt_miscdev.minor, rc); 373c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck goto err_out_reboot; 3741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n", 3761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout, nowayout); 3771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 3791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 380c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeckerr_out_reboot: 381c6cb13aead3a3cf5bd3e2cfa945602d5cd7825cdWim Van Sebroeck unregister_reboot_notifier(&wdt_notifier); 3821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_region2: 3831780de41406d783aa57459ba636a09aeda21d180Alan Cox if (wdt_stop != 0x45 && wdt_stop != wdt_start) 3841780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_stop, 1); 3851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_region1: 3861780de41406d783aa57459ba636a09aeda21d180Alan Cox release_region(wdt_start, 1); 3871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out: 3881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return rc; 3891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_init(sbc60xxwdt_init); 3921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_exit(sbc60xxwdt_unload); 3931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>"); 3951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver"); 3961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_LICENSE("GPL"); 3971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 398