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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [advantechwdt.c] - Rev 1765
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/* * Advantech Single Board Computer WDT driver for Linux 2.4.x * * (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 */ #include <linux/config.h> #include <linux/module.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/ioport.h> #include <linux/fcntl.h> #include <asm/io.h> #include <asm/uaccess.h> #include <asm/system.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/init.h> 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; static int wdt_start = 0x443; static int wd_margin = 60; /* 60 sec default timeout */ #ifdef CONFIG_WATCHDOG_NOWAYOUT static int nowayout = 1; #else static int nowayout = 0; #endif MODULE_PARM(nowayout,"i"); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); /* * Kernel methods. */ #ifndef MODULE static int __init adv_setup(char *str) { int ints[4]; str = get_options(str, ARRAY_SIZE(ints), ints); if(ints[0] > 0){ wdt_stop = ints[1]; if(ints[0] > 1) wdt_start = ints[2]; } return 1; } __setup("advwdt=", adv_setup); #endif /* !MODULE */ MODULE_PARM(wdt_stop, "i"); MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); MODULE_PARM(wdt_start, "i"); MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); static void advwdt_ping(void) { /* Write a watchdog value */ outb_p(wd_margin, wdt_start); } static void advwdt_disable(void) { inb_p(wdt_stop); } static ssize_t advwdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { /* Can't seek (pwrite) on this device */ if (ppos != &file->f_pos) return -ESPIPE; 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_margin; static struct watchdog_info ident = { options: WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, firmware_version: 0, identity: "Advantech WDT" }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, (int *)arg); case WDIOC_KEEPALIVE: advwdt_ping(); break; case WDIOC_SETTIMEOUT: if (get_user(new_margin, (int *)arg)) return -EFAULT; if ((new_margin < 1) || (new_margin > 63)) return -EINVAL; wd_margin = new_margin; advwdt_ping(); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(wd_margin, (int *)arg); case WDIOC_SETOPTIONS: { int options, retval = -EINVAL; if (get_user(options, (int *)arg)) return -EFAULT; if (options & WDIOS_DISABLECARD) { advwdt_disable(); retval = 0; } if (options & WDIOS_ENABLECARD) { advwdt_ping(); retval = 0; } return retval; } default: return -ENOTTY; } 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 0; } static int advwdt_close(struct inode *inode, struct file *file) { if (adv_expect_close == 42) { advwdt_disable(); } else { printk(KERN_CRIT "advancetechwdt: 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 = { advwdt_notify_sys, NULL, 0 }; static int __init advwdt_init(void) { printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n"); misc_register(&advwdt_miscdev); if(wdt_stop != wdt_start) request_region(wdt_stop, 1, "Advantech WDT"); request_region(wdt_start, 1, "Advantech WDT"); register_reboot_notifier(&advwdt_notifier); return 0; } 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"); EXPORT_NO_SYMBOLS; /* end of advantechwdt.c */