/* * Advantech Single Board Computer WDT driver * * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> * * Based on acquirewdt.c which is based on wdt.c. * Original copyright messages: * * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. * http://www.redhat.com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide * warranty for any of this software. This material is provided * "AS-IS" and at no charge. * * (c) Copyright 1995 Alan Cox <alan@redhat.com> * * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT * * 16-Oct-2002 Rob Radez <rob@osinvestor.com> * Clean up ioctls, clean up init + exit, add expect close support, * add wdt_start and wdt_stop as parameters. */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/fs.h> #include <linux/ioport.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/init.h> #include <asm/io.h> #include <asm/uaccess.h> #include <asm/system.h> #define WATCHDOG_NAME "Advantech WDT" #define PFX WATCHDOG_NAME ": " #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ static unsigned long advwdt_is_open; static char adv_expect_close; /* * You must set these - there is no sane way to probe for this board. * * To enable or restart, write the timeout value in seconds (1 to 63) * to I/O port wdt_start. To disable, read I/O port wdt_stop. * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but * check your manual (at least the PCA-6159 seems to be different - * the manual says wdt_stop is 0x43, not 0x443). * (0x43 is also a write-only control register for the 8254 timer!) */ static int wdt_stop = 0x443; module_param(wdt_stop, int, 0); MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); static int wdt_start = 0x443; module_param(wdt_start, int, 0); MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); static int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); /* * Kernel methods. */ static void advwdt_ping(void) { /* Write a watchdog value */ outb_p(timeout, wdt_start); } static void advwdt_disable(void) { inb_p(wdt_stop); } static ssize_t advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { if (count) { if (!nowayout) { size_t i; adv_expect_close = 0; for (i = 0; i != count; i++) { char c; if (get_user(c, buf+i)) return -EFAULT; if (c == 'V') adv_expect_close = 42; } } advwdt_ping(); } return count; } static int advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int new_timeout; void __user *argp = (void __user *)arg; int __user *p = argp; static struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "Advantech WDT", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: advwdt_ping(); break; case WDIOC_SETTIMEOUT: if (get_user(new_timeout, p)) return -EFAULT; if ((new_timeout < 1) || (new_timeout > 63)) return -EINVAL; timeout = new_timeout; advwdt_ping(); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(timeout, p); case WDIOC_SETOPTIONS: { int options, retval = -EINVAL; if (get_user(options, p)) return -EFAULT; if (options & WDIOS_DISABLECARD) { advwdt_disable(); retval = 0; } if (options & WDIOS_ENABLECARD) { advwdt_ping(); retval = 0; } return retval; } default: return -ENOIOCTLCMD; } return 0; } static int advwdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &advwdt_is_open)) return -EBUSY; /* * Activate */ advwdt_ping(); return nonseekable_open(inode, file); } static int advwdt_close(struct inode *inode, struct file *file) { if (adv_expect_close == 42) { advwdt_disable(); } else { printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); advwdt_ping(); } clear_bit(0, &advwdt_is_open); adv_expect_close = 0; return 0; } /* * Notifier for system down */ static int advwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) { /* Turn the WDT off */ advwdt_disable(); } return NOTIFY_DONE; } /* * Kernel Interfaces */ static struct file_operations advwdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = advwdt_write, .ioctl = advwdt_ioctl, .open = advwdt_open, .release = advwdt_close, }; static struct miscdevice advwdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &advwdt_fops, }; /* * The WDT needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block advwdt_notifier = { .notifier_call = advwdt_notify_sys, }; static int __init advwdt_init(void) { int ret; printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n"); if (timeout < 1 || timeout > 63) { timeout = WATCHDOG_TIMEOUT; printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n", timeout); } if (wdt_stop != wdt_start) { if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_stop); ret = -EIO; goto out; } } if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_start); ret = -EIO; goto unreg_stop; } ret = register_reboot_notifier(&advwdt_notifier); if (ret != 0) { printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret); goto unreg_regions; } ret = misc_register(&advwdt_miscdev); if (ret != 0) { printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); goto unreg_reboot; } printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", timeout, nowayout); out: return ret; unreg_reboot: unregister_reboot_notifier(&advwdt_notifier); unreg_regions: release_region(wdt_start, 1); unreg_stop: if (wdt_stop != wdt_start) release_region(wdt_stop, 1); goto out; } static void __exit advwdt_exit(void) { misc_deregister(&advwdt_miscdev); unregister_reboot_notifier(&advwdt_notifier); if(wdt_stop != wdt_start) release_region(wdt_stop,1); release_region(wdt_start,1); } module_init(advwdt_init); module_exit(advwdt_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>"); MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);