sbc60xxwdt.c revision 82eb7c5059de64bd43f6b3cf3f128470f2b3fb83
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 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 09/5 - 2001 [smj@oro.net] fixed fop_write to "return 1" on success 201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 12/4 - 2002 [rob@osinvestor.com] eliminate fop_read 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * fix possible wdt_is_open race 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * add CONFIG_WATCHDOG_NOWAYOUT support 231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * remove lock_kernel/unlock_kernel pairs 241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added KERN_* to printk's 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * got rid of extraneous comments 261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * changed watchdog_info to correctly reflect what the driver offers 271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, WDIOC_SETTIMEOUT, 281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls 291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces 301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * use module_param 311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * made timeout (the emulated heartbeat) a module_param 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * made the keepalive ping an internal subroutine 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * made wdt_stop and wdt_start module params 341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added extra printk's for startup problems 351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * added MODULE_AUTHOR and MODULE_DESCRIPTION info 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This WDT driver is different from the other Linux WDT 391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * drivers in the following ways: 401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * *) The driver will ping the watchdog by itself, because this 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * particular WDT has a very short timeout (one second) and it 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * would be insane to count on any userspace daemon always 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * getting scheduled within that time frame. 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/module.h> 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/moduleparam.h> 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/types.h> 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/timer.h> 511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/jiffies.h> 521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/miscdevice.h> 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/watchdog.h> 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/fs.h> 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/ioport.h> 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/notifier.h> 571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/reboot.h> 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/init.h> 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <asm/io.h> 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <asm/uaccess.h> 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <asm/system.h> 631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define OUR_NAME "sbc60xxwdt" 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define PFX OUR_NAME ": " 661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * You must set these - The driver cannot probe for the settings 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_stop = 0x45; 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(wdt_stop, int, 0); 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)"); 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int wdt_start = 0x443; 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(wdt_start, int, 0); 771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)"); 781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The 60xx board can use watchdog timeout values from one second 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * to several minutes. The default is one second, so if we reset 821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the watchdog every ~250ms we should be safe. 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define WDT_INTERVAL (HZ/4+1) 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * We must not require too good response from the userspace daemon. 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Here we require the userspace daemon to send us a heartbeat 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * char to /dev/watchdog every 30 seconds. 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If the daemon pulses us every 25 seconds, we can still afford 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * a 5 second scheduling delay on the (high priority) daemon. That 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * should be sufficient for a box under any load. 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(timeout, int, 0); 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1014bfdf37830111321e2cd1fe0102dd776ce93194dAndrey Paninstatic int nowayout = WATCHDOG_NOWAYOUT; 1021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(nowayout, int, 0); 103bffda5c87cf60d27a27f2e862c82c474f8e89767Wim Van SebroeckMODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_timer_ping(unsigned long); 10682eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slabystatic DEFINE_TIMER(timer, wdt_timer_ping, 0, 0); 1071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic unsigned long next_heartbeat; 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic unsigned long wdt_is_open; 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic char wdt_expect_close; 1101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Whack the dog 1131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_timer_ping(unsigned long data) 1161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* If we got a heartbeat pulse within the WDT_US_INTERVAL 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we agree to ping the WDT 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(time_before(jiffies, next_heartbeat)) 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Ping the WDT by reading from wdt_start */ 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds inb_p(wdt_start); 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Re-set the timer interval */ 12582eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slaby mod_timer(&timer, jiffies + WDT_INTERVAL); 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } else { 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n"); 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Utility routines 1331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_startup(void) 1361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds next_heartbeat = jiffies + (timeout * HZ); 1381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Start the timer */ 14082eb7c5059de64bd43f6b3cf3f128470f2b3fb83Jiri Slaby mod_timer(&timer, jiffies + WDT_INTERVAL); 1411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "Watchdog timer is now enabled.\n"); 1421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_turnoff(void) 1451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Stop the timer */ 1471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds del_timer(&timer); 1481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds inb_p(wdt_stop); 1491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); 1501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void wdt_keepalive(void) 1531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* user land ping */ 1551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds next_heartbeat = jiffies + (timeout * HZ); 1561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * /dev/watchdog handling 1601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos) 1631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* See if we got the magic character 'V' and reload the timer */ 1651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(count) 1661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 1671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!nowayout) 1681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 1691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds size_t ofs; 1701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* note: just in case someone wrote the magic character 1721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * five months ago... */ 1731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 0; 1741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* scan to see whether or not we got the magic character */ 1761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds for(ofs = 0; ofs != count; ofs++) 1771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 1781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds char c; 1791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(get_user(c, buf+ofs)) 1801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EFAULT; 1811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(c == 'V') 1821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 42; 1831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Well, anyhow someone wrote to us, we should return that favour */ 1871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_keepalive(); 1881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return count; 1901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int fop_open(struct inode * inode, struct file * file) 1931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds nonseekable_open(inode, file); 1951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Just in case we're already talking to someone... */ 1971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(test_and_set_bit(0, &wdt_is_open)) 1981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EBUSY; 1991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (nowayout) 2011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __module_get(THIS_MODULE); 2021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Good, fire up the show */ 2041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_startup(); 2051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 2061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int fop_close(struct inode * inode, struct file * file) 2091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(wdt_expect_close == 42) 2111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 2121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else { 2131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds del_timer(&timer); 2141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n"); 2151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clear_bit(0, &wdt_is_open); 2171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_expect_close = 0; 2181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 2191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 2221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long arg) 2231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds void __user *argp = (void __user *)arg; 2251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int __user *p = argp; 2261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds static struct watchdog_info ident= 2271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 2281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, 2291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .firmware_version = 1, 2301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .identity = "SBC60xx", 2311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds }; 2321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch(cmd) 2341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 2351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds default: 236795b89d207d8ff5397f9ff1f4d44662aa7c821fcSamuel Tardieu return -ENOTTY; 2371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_GETSUPPORT: 2381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; 2391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_GETSTATUS: 2401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_GETBOOTSTATUS: 2411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return put_user(0, p); 2421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_KEEPALIVE: 2431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_keepalive(); 2441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 2451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_SETOPTIONS: 2461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 2471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int new_options, retval = -EINVAL; 2481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(get_user(new_options, p)) 2501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EFAULT; 2511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(new_options & WDIOS_DISABLECARD) { 2531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 2541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds retval = 0; 2551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(new_options & WDIOS_ENABLECARD) { 2581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_startup(); 2591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds retval = 0; 2601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return retval; 2631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_SETTIMEOUT: 2651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 2661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int new_timeout; 2671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(get_user(new_timeout, p)) 2691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EFAULT; 2701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */ 2721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EINVAL; 2731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout = new_timeout; 2751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_keepalive(); 2761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Fall through */ 2771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case WDIOC_GETTIMEOUT: 2791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return put_user(timeout, p); 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, 2891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .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{ 3051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 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 3151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct notifier_block wdt_notifier= 3161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .notifier_call = wdt_notify_sys, 3181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 3191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void __exit sbc60xxwdt_unload(void) 3211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_turnoff(); 3231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Deregister */ 3251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds misc_deregister(&wdt_miscdev); 3261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unregister_reboot_notifier(&wdt_notifier); 3281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((wdt_stop != 0x45) && (wdt_stop != wdt_start)) 3291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds release_region(wdt_stop,1); 3301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds release_region(wdt_start,1); 3311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int __init sbc60xxwdt_init(void) 3341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int rc = -EBUSY; 3361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */ 3381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 3391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout = WATCHDOG_TIMEOUT; 3401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n", 3411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout); 3421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!request_region(wdt_start, 1, "SBC 60XX WDT")) 3451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 3461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 3471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_start); 3481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = -EIO; 3491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out; 3501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* We cannot reserve 0x45 - the kernel already has! */ 3531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((wdt_stop != 0x45) && (wdt_stop != wdt_start)) 3541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 3551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!request_region(wdt_stop, 1, "SBC 60XX WDT")) 3561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 3571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 3581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_stop); 3591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = -EIO; 3601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_region1; 3611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = misc_register(&wdt_miscdev); 3651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (rc) 3661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 3671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", 3681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds wdt_miscdev.minor, rc); 3691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_region2; 3701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc = register_reboot_notifier(&wdt_notifier); 3731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (rc) 3741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds { 3751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", 3761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds rc); 3771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err_out_miscdev; 3781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO PFX "WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n", 3811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds timeout, nowayout); 3821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 3841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_miscdev: 3861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds misc_deregister(&wdt_miscdev); 3871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_region2: 3881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((wdt_stop != 0x45) && (wdt_stop != wdt_start)) 3891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds release_region(wdt_stop,1); 3901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out_region1: 3911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds release_region(wdt_start,1); 3921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr_out: 3931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return rc; 3941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 3951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_init(sbc60xxwdt_init); 3971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_exit(sbc60xxwdt_unload); 3981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>"); 4001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver"); 4011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_LICENSE("GPL"); 4021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 403