/* * Industrial Computer Source WDT500/501 driver * * (c) Copyright 1996-1997 Alan Cox , 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 * * Release 0.10. * * Fixes * Dave Gregorich : Modularisation and minor bugs * Alan Cox : Added the watchdog ioctl() stuff * Alan Cox : Fixed the reboot problem (as noted by * Matt Crocker). * Alan Cox : Added wdt= boot option * Alan Cox : Cleaned up copy/user stuff * Tim Hockin : Added insmod parameters, comment cleanup * Parameterized timeout * Tigran Aivazian : Restructured wdt_init() to handle failures * Joel Becker : Added WDIOC_GET/SETTIMEOUT * Matt Domsch : Added nowayout module option */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "wd501p.h" static unsigned long wdt_is_open; static char expect_close; /* * Module parameters */ #define WD_TIMO 60 /* Default heartbeat = 60 seconds */ static int heartbeat = WD_TIMO; static int wd_heartbeat; module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0>8, WDT_COUNT0+ctr); } /** * wdt_start: * * Start the watchdog driver. */ static int wdt_start(void) { inb_p(WDT_DC); /* Disable watchdog */ wdt_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */ wdt_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */ wdt_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */ wdt_ctr_load(0, 8948); /* Count at 100Hz */ wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */ wdt_ctr_load(2,65535); /* Length of reset pulse */ outb_p(0, WDT_DC); /* Enable watchdog */ return 0; } /** * wdt_stop: * * Stop the watchdog driver. */ static int wdt_stop (void) { /* Turn the card off */ inb_p(WDT_DC); /* Disable watchdog */ wdt_ctr_load(2,0); /* 0 length reset pulses now */ return 0; } /** * wdt_ping: * * Reload counter one with the watchdog heartbeat. We don't bother reloading * the cascade counter. */ static int wdt_ping(void) { /* Write a watchdog value */ inb_p(WDT_DC); /* Disable watchdog */ wdt_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */ wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */ outb_p(0, WDT_DC); /* Enable watchdog */ return 0; } /** * wdt_set_heartbeat: * @t: the new heartbeat value that needs to be set. * * Set a new heartbeat value for the watchdog device. If the heartbeat value is * incorrect we keep the old value and return -EINVAL. If successfull we * return 0. */ static int wdt_set_heartbeat(int t) { if ((t < 1) || (t > 65535)) return -EINVAL; heartbeat = t; wd_heartbeat = t * 100; return 0; } /** * wdt_get_status: * @status: the new status. * * Extract the status information from a WDT watchdog device. There are * several board variants so we have to know which bits are valid. Some * bits default to one and some to zero in order to be maximally painful. * * we then map the bits onto the status ioctl flags. */ static int wdt_get_status(int *status) { unsigned char new_status=inb_p(WDT_SR); *status=0; if (new_status & WDC_SR_ISOI0) *status |= WDIOF_EXTERN1; if (new_status & WDC_SR_ISII1) *status |= WDIOF_EXTERN2; #ifdef CONFIG_WDT_501 if (!(new_status & WDC_SR_TGOOD)) *status |= WDIOF_OVERHEAT; if (!(new_status & WDC_SR_PSUOVER)) *status |= WDIOF_POWEROVER; if (!(new_status & WDC_SR_PSUUNDR)) *status |= WDIOF_POWERUNDER; if (tachometer) { if (!(new_status & WDC_SR_FANGOOD)) *status |= WDIOF_FANFAULT; } #endif /* CONFIG_WDT_501 */ return 0; } #ifdef CONFIG_WDT_501 /** * wdt_get_temperature: * * Reports the temperature in degrees Fahrenheit. The API is in * farenheit. It was designed by an imperial measurement luddite. */ static int wdt_get_temperature(int *temperature) { unsigned short c=inb_p(WDT_RT); *temperature = (c * 11 / 15) + 7; return 0; } #endif /* CONFIG_WDT_501 */ /** * wdt_interrupt: * @irq: Interrupt number * @dev_id: Unused as we don't allow multiple devices. * @regs: Unused. * * Handle an interrupt from the board. These are raised when the status * map changes in what the board considers an interesting way. That means * a failure condition occurring. */ static irqreturn_t wdt_interrupt(int irq, void *dev_id, struct pt_regs *regs) { /* * Read the status register see what is up and * then printk it. */ unsigned char status=inb_p(WDT_SR); printk(KERN_CRIT "WDT status %d\n", status); #ifdef CONFIG_WDT_501 if (!(status & WDC_SR_TGOOD)) printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT)); if (!(status & WDC_SR_PSUOVER)) printk(KERN_CRIT "PSU over voltage.\n"); if (!(status & WDC_SR_PSUUNDR)) printk(KERN_CRIT "PSU under voltage.\n"); if (tachometer) { if (!(status & WDC_SR_FANGOOD)) printk(KERN_CRIT "Possible fan fault.\n"); } #endif /* CONFIG_WDT_501 */ if (!(status & WDC_SR_WCCR)) #ifdef SOFTWARE_REBOOT #ifdef ONLY_TESTING printk(KERN_CRIT "Would Reboot.\n"); #else printk(KERN_CRIT "Initiating system reboot.\n"); emergency_restart(); #endif #else printk(KERN_CRIT "Reset in 5ms.\n"); #endif return IRQ_HANDLED; } /** * wdt_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 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { 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; } } wdt_ping(); } return count; } /** * wdt_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. We only actually usefully support * querying capabilities and current status. */ static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; int new_heartbeat; int status; static struct watchdog_info ident = { .options = WDIOF_SETTIMEOUT| WDIOF_MAGICCLOSE| WDIOF_KEEPALIVEPING, .firmware_version = 1, .identity = "WDT500/501", }; /* Add options according to the card we have */ ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2); #ifdef CONFIG_WDT_501 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER); if (tachometer) ident.options |= WDIOF_FANFAULT; #endif /* CONFIG_WDT_501 */ switch(cmd) { default: return -ENOIOCTLCMD; case WDIOC_GETSUPPORT: return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; case WDIOC_GETSTATUS: wdt_get_status(&status); return put_user(status, p); case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: wdt_ping(); return 0; case WDIOC_SETTIMEOUT: if (get_user(new_heartbeat, p)) return -EFAULT; if (wdt_set_heartbeat(new_heartbeat)) return -EINVAL; wdt_ping(); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(heartbeat, p); } } /** * wdt_open: * @inode: inode of device * @file: file handle to device * * The watchdog device has been opened. The watchdog device is single * open and on opening we load the counters. Counter zero is a 100Hz * cascade, into counter 1 which downcounts to reboot. When the counter * triggers counter 2 downcounts the length of the reset pulse which * set set to be as long as possible. */ static int wdt_open(struct inode *inode, struct file *file) { if(test_and_set_bit(0, &wdt_is_open)) return -EBUSY; /* * Activate */ wdt_start(); return nonseekable_open(inode, file); } /** * wdt_release: * @inode: inode to board * @file: file handle to board * * The watchdog has a configurable API. There is a religious dispute * between people who want their watchdog to be able to shut down and * those who want to be sure if the watchdog manager dies the machine * reboots. In the former case we disable the counters, in the latter * case you have to open it again very soon. */ static int wdt_release(struct inode *inode, struct file *file) { if (expect_close == 42) { wdt_stop(); clear_bit(0, &wdt_is_open); } else { printk(KERN_CRIT "wdt: WDT device closed unexpectedly. WDT will not stop!\n"); wdt_ping(); } expect_close = 0; return 0; } #ifdef CONFIG_WDT_501 /** * wdt_temp_read: * @file: file handle to the watchdog board * @buf: buffer to write 1 byte into * @count: length of buffer * @ptr: offset (no seek allowed) * * Temp_read reports the temperature in degrees Fahrenheit. The API is in * farenheit. It was designed by an imperial measurement luddite. */ static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) { int temperature; if (wdt_get_temperature(&temperature)) return -EFAULT; if (copy_to_user (buf, &temperature, 1)) return -EFAULT; return 1; } /** * wdt_temp_open: * @inode: inode of device * @file: file handle to device * * The temperature device has been opened. */ static int wdt_temp_open(struct inode *inode, struct file *file) { return nonseekable_open(inode, file); } /** * wdt_temp_release: * @inode: inode to board * @file: file handle to board * * The temperature device has been closed. */ static int wdt_temp_release(struct inode *inode, struct file *file) { return 0; } #endif /* CONFIG_WDT_501 */ /** * notify_sys: * @this: our notifier block * @code: the event being reported * @unused: unused * * Our notifier is called on system shutdowns. We want to turn the card * off at reboot otherwise the machine will reboot again during memory * test or worse yet during the following fsck. This would suck, in fact * trust me - if it happens it does suck. */ static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if(code==SYS_DOWN || code==SYS_HALT) { /* Turn the card off */ wdt_stop(); } return NOTIFY_DONE; } /* * Kernel Interfaces */ static struct file_operations wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = wdt_write, .ioctl = wdt_ioctl, .open = wdt_open, .release = wdt_release, }; static struct miscdevice wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &wdt_fops, }; #ifdef CONFIG_WDT_501 static struct file_operations wdt_temp_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = wdt_temp_read, .open = wdt_temp_open, .release = wdt_temp_release, }; static struct miscdevice temp_miscdev = { .minor = TEMP_MINOR, .name = "temperature", .fops = &wdt_temp_fops, }; #endif /* CONFIG_WDT_501 */ /* * The WDT card needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block wdt_notifier = { .notifier_call = wdt_notify_sys, }; /** * cleanup_module: * * Unload the watchdog. You cannot do this with any file handles open. * If your watchdog is set to continue ticking on close and you unload * it, well it keeps ticking. We won't get the interrupt but the board * will not touch PC memory so all is fine. You just have to load a new * module in 60 seconds or reboot. */ static void __exit wdt_exit(void) { misc_deregister(&wdt_miscdev); #ifdef CONFIG_WDT_501 misc_deregister(&temp_miscdev); #endif /* CONFIG_WDT_501 */ unregister_reboot_notifier(&wdt_notifier); free_irq(irq, NULL); release_region(io,8); } /** * wdt_init: * * Set up the WDT watchdog board. All we have to do is grab the * resources we require and bitch if anyone beat us to them. * The open() function will actually kick the board off. */ static int __init wdt_init(void) { int ret; /* Check that the heartbeat value is within it's range ; if not reset to the default */ if (wdt_set_heartbeat(heartbeat)) { wdt_set_heartbeat(WD_TIMO); printk(KERN_INFO "wdt: heartbeat value must be 0