/* * Wdt977 0.02: A Watchdog Device for Netwinder W83977AF chip * * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>) * * ----------------------- * * 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. * * ----------------------- * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts * from minutes to seconds. * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in * nwwatchdog_init. */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/config.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/miscdevice.h> #include <linux/init.h> #include <linux/watchdog.h> #include <asm/io.h> #include <asm/system.h> #include <asm/mach-types.h> #include <asm/uaccess.h> #define WATCHDOG_MINOR 130 #define DEFAULT_TIMEOUT 1 /* default timeout = 1 minute */ static int timeout = DEFAULT_TIMEOUT*60; /* TO in seconds from user */ static int timeoutM = DEFAULT_TIMEOUT; /* timeout in minutes */ static unsigned long timer_alive; static int testmode; static char expect_close; module_param(timeout, int, 0); MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (60..15300), default=60"); module_param(testmode, int, 0); MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0"); #ifdef CONFIG_WATCHDOG_NOWAYOUT static int nowayout = 1; #else static int nowayout = 0; #endif module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); /* This is kicking the watchdog by simply re-writing the timeout to reg. 0xF2 */ static int kick_wdog(void) { /* * Refresh the timer. */ /* unlock the SuperIO chip */ outb(0x87,0x370); outb(0x87,0x370); /* select device Aux2 (device=8) and kicks watchdog reg F2 */ /* F2 has the timeout in minutes */ outb(0x07,0x370); outb(0x08,0x371); outb(0xF2,0x370); outb(timeoutM,0x371); /* lock the SuperIO chip */ outb(0xAA,0x370); return 0; } /* * Allow only one person to hold it open */ static int wdt977_open(struct inode *inode, struct file *file) { if( test_and_set_bit(0,&timer_alive) ) return -EBUSY; /* convert seconds to minutes, rounding up */ timeoutM = timeout + 59; timeoutM /= 60; if (nowayout) { __module_get(THIS_MODULE); /* do not permit disabling the watchdog by writing 0 to reg. 0xF2 */ if (!timeoutM) timeoutM = DEFAULT_TIMEOUT; } if (machine_is_netwinder()) { /* we have a hw bug somewhere, so each 977 minute is actually only 30sec * this limits the max timeout to half of device max of 255 minutes... */ timeoutM += timeoutM; } /* max timeout value = 255 minutes (0xFF). Write 0 to disable WatchDog. */ if (timeoutM > 255) timeoutM = 255; /* convert seconds to minutes */ printk(KERN_INFO "Wdt977 Watchdog activated: timeout = %d sec, nowayout = %i, testmode = %i.\n", machine_is_netwinder() ? (timeoutM>>1)*60 : timeoutM*60, nowayout, testmode); /* unlock the SuperIO chip */ outb(0x87,0x370); outb(0x87,0x370); /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 * F2 has the timeout in minutes * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) * at timeout, and to reset timer on kbd/mouse activity (not impl.) * F4 is used to just clear the TIMEOUT'ed state (bit 0) */ outb(0x07,0x370); outb(0x08,0x371); outb(0xF2,0x370); outb(timeoutM,0x371); outb(0xF3,0x370); outb(0x00,0x371); /* another setting is 0E for kbd/mouse/LED */ outb(0xF4,0x370); outb(0x00,0x371); /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ /* in test mode watch the bit 1 on F4 to indicate "triggered" */ if (!testmode) { outb(0x07,0x370); outb(0x07,0x371); outb(0xE6,0x370); outb(0x08,0x371); } /* lock the SuperIO chip */ outb(0xAA,0x370); return 0; } static int wdt977_release(struct inode *inode, struct file *file) { /* * Shut off the timer. * Lock it in if it's a module and we set nowayout */ if (expect_close == 42) { /* unlock the SuperIO chip */ outb(0x87,0x370); outb(0x87,0x370); /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 * F3 is reset to its default state * F4 can clear the TIMEOUT'ed state (bit 0) - back to default * We can not use GP17 as a PowerLed, as we use its usage as a RedLed */ outb(0x07,0x370); outb(0x08,0x371); outb(0xF2,0x370); outb(0xFF,0x371); outb(0xF3,0x370); outb(0x00,0x371); outb(0xF4,0x370); outb(0x00,0x371); outb(0xF2,0x370); outb(0x00,0x371); /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ outb(0x07,0x370); outb(0x07,0x371); outb(0xE6,0x370); outb(0x08,0x371); /* lock the SuperIO chip */ outb(0xAA,0x370); clear_bit(0,&timer_alive); printk(KERN_INFO "Wdt977 Watchdog: shutdown\n"); } else { printk(KERN_CRIT "WDT device closed unexpectedly. WDT will not stop!\n"); } expect_close = 0; return 0; } /* * wdt977_write: * @file: file handle to the watchdog * @buf: buffer to write (unused as data does not matter here * @count: count of bytes * @ppos: pointer to the position to write. No seeks allowed * * A write to a watchdog device is defined as a keepalive signal. Any * write of data will do, as we we don't define content meaning. */ static ssize_t wdt977_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; /* In case it was set long ago */ expect_close = 0; for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') expect_close = 42; } } kick_wdog(); } return count; } /* * wdt977_ioctl: * @inode: inode of the device * @file: file handle to the device * @cmd: watchdog command * @arg: argument pointer * * The watchdog API defines a common set of functions for all watchdogs * according to their available features. */ static struct watchdog_info ident = { .options = WDIOF_SETTIMEOUT, .identity = "Winbond 83977" }; static int wdt977_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int temp; switch(cmd) { default: return -ENOTTY; case WDIOC_GETSUPPORT: return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)) ? -EFAULT : 0; case WDIOC_GETBOOTSTATUS: return put_user(0, (int *) arg); case WDIOC_GETSTATUS: /* unlock the SuperIO chip */ outb(0x87,0x370); outb(0x87,0x370); /* select device Aux2 (device=8) and read watchdog reg F4 */ outb(0x07,0x370); outb(0x08,0x371); outb(0xF4,0x370); temp = inb(0x371); /* lock the SuperIO chip */ outb(0xAA,0x370); /* return info if "expired" in test mode */ return put_user(temp & 1, (int *) arg); case WDIOC_KEEPALIVE: kick_wdog(); return 0; case WDIOC_SETTIMEOUT: if (copy_from_user(&temp, (int *) arg, sizeof(int))) return -EFAULT; /* convert seconds to minutes, rounding up */ temp += 59; temp /= 60; /* we have a hw bug somewhere, so each 977 minute is actually only 30sec * this limits the max timeout to half of device max of 255 minutes... */ if (machine_is_netwinder()) { temp += temp; } /* Sanity check */ if (temp < 0 || temp > 255) return -EINVAL; if (!temp && nowayout) return -EINVAL; timeoutM = temp; kick_wdog(); return 0; } } static struct file_operations wdt977_fops= { .owner = THIS_MODULE, .write = wdt977_write, .ioctl = wdt977_ioctl, .open = wdt977_open, .release = wdt977_release, }; static struct miscdevice wdt977_miscdev= { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &wdt977_fops }; static int __init nwwatchdog_init(void) { int retval; if (!machine_is_netwinder()) return -ENODEV; retval = misc_register(&wdt977_miscdev); if (!retval) printk(KERN_INFO "Wdt977 Watchdog sleeping.\n"); return retval; } static void __exit nwwatchdog_exit(void) { misc_deregister(&wdt977_miscdev); } module_init(nwwatchdog_init); module_exit(nwwatchdog_exit); MODULE_DESCRIPTION("W83977AF Watchdog driver"); MODULE_LICENSE("GPL");