/* * sma cpu5 watchdog driver * * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de> * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/miscdevice.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/ioport.h> #include <linux/timer.h> #include <linux/completion.h> #include <linux/jiffies.h> #include <linux/io.h> #include <linux/uaccess.h> #include <linux/watchdog.h> /* adjustable parameters */ static int verbose; static int port = 0x91; static int ticks = 10000; static spinlock_t cpu5wdt_lock; #define PFX "cpu5wdt: " #define CPU5WDT_EXTENT 0x0A #define CPU5WDT_STATUS_REG 0x00 #define CPU5WDT_TIME_A_REG 0x02 #define CPU5WDT_TIME_B_REG 0x03 #define CPU5WDT_MODE_REG 0x04 #define CPU5WDT_TRIGGER_REG 0x07 #define CPU5WDT_ENABLE_REG 0x08 #define CPU5WDT_RESET_REG 0x09 #define CPU5WDT_INTERVAL (HZ/10+1) /* some device data */ static struct { struct completion stop; int running; struct timer_list timer; int queue; int default_ticks; unsigned long inuse; } cpu5wdt_device; /* generic helper functions */ static void cpu5wdt_trigger(unsigned long unused) { if (verbose > 2) printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks); if (cpu5wdt_device.running) ticks--; spin_lock(&cpu5wdt_lock); /* keep watchdog alive */ outb(1, port + CPU5WDT_TRIGGER_REG); /* requeue?? */ if (cpu5wdt_device.queue && ticks) mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL); else { /* ticks doesn't matter anyway */ complete(&cpu5wdt_device.stop); } spin_unlock(&cpu5wdt_lock); } static void cpu5wdt_reset(void) { ticks = cpu5wdt_device.default_ticks; if (verbose) printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks); } static void cpu5wdt_start(void) { unsigned long flags; spin_lock_irqsave(&cpu5wdt_lock, flags); if (!cpu5wdt_device.queue) { cpu5wdt_device.queue = 1; outb(0, port + CPU5WDT_TIME_A_REG); outb(0, port + CPU5WDT_TIME_B_REG); outb(1, port + CPU5WDT_MODE_REG); outb(0, port + CPU5WDT_RESET_REG); outb(0, port + CPU5WDT_ENABLE_REG); mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL); } /* if process dies, counter is not decremented */ cpu5wdt_device.running++; spin_unlock_irqrestore(&cpu5wdt_lock, flags); } static int cpu5wdt_stop(void) { unsigned long flags; spin_lock_irqsave(&cpu5wdt_lock, flags); if (cpu5wdt_device.running) cpu5wdt_device.running = 0; ticks = cpu5wdt_device.default_ticks; spin_unlock_irqrestore(&cpu5wdt_lock, flags); if (verbose) printk(KERN_CRIT PFX "stop not possible\n"); return -EIO; } /* filesystem operations */ static int cpu5wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &cpu5wdt_device.inuse)) return -EBUSY; return nonseekable_open(inode, file); } static int cpu5wdt_release(struct inode *inode, struct file *file) { clear_bit(0, &cpu5wdt_device.inuse); return 0; } static long cpu5wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; unsigned int value; static struct watchdog_info ident = { .options = WDIOF_CARDRESET, .identity = "CPU5 WDT", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: value = inb(port + CPU5WDT_STATUS_REG); value = (value >> 2) & 1; return put_user(value, p); case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_SETOPTIONS: if (get_user(value, p)) return -EFAULT; if (value & WDIOS_ENABLECARD) cpu5wdt_start(); if (value & WDIOS_DISABLECARD) cpu5wdt_stop(); break; case WDIOC_KEEPALIVE: cpu5wdt_reset(); break; default: return -ENOTTY; } return 0; } static ssize_t cpu5wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { if (!count) return -EIO; cpu5wdt_reset(); return count; } static const struct file_operations cpu5wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .unlocked_ioctl = cpu5wdt_ioctl, .open = cpu5wdt_open, .write = cpu5wdt_write, .release = cpu5wdt_release, }; static struct miscdevice cpu5wdt_misc = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &cpu5wdt_fops, }; /* init/exit function */ static int __devinit cpu5wdt_init(void) { unsigned int val; int err; if (verbose) printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose); init_completion(&cpu5wdt_device.stop); spin_lock_init(&cpu5wdt_lock); cpu5wdt_device.queue = 0; setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0); cpu5wdt_device.default_ticks = ticks; if (!request_region(port, CPU5WDT_EXTENT, PFX)) { printk(KERN_ERR PFX "request_region failed\n"); err = -EBUSY; goto no_port; } /* watchdog reboot? */ val = inb(port + CPU5WDT_STATUS_REG); val = (val >> 2) & 1; if (!val) printk(KERN_INFO PFX "sorry, was my fault\n"); err = misc_register(&cpu5wdt_misc); if (err < 0) { printk(KERN_ERR PFX "misc_register failed\n"); goto no_misc; } printk(KERN_INFO PFX "init success\n"); return 0; no_misc: release_region(port, CPU5WDT_EXTENT); no_port: return err; } static int __devinit cpu5wdt_init_module(void) { return cpu5wdt_init(); } static void __devexit cpu5wdt_exit(void) { if (cpu5wdt_device.queue) { cpu5wdt_device.queue = 0; wait_for_completion(&cpu5wdt_device.stop); } misc_deregister(&cpu5wdt_misc); release_region(port, CPU5WDT_EXTENT); } static void __devexit cpu5wdt_exit_module(void) { cpu5wdt_exit(); } /* module entry points */ module_init(cpu5wdt_init_module); module_exit(cpu5wdt_exit_module); MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>"); MODULE_DESCRIPTION("sma cpu5 watchdog driver"); MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); module_param(port, int, 0); MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91"); module_param(verbose, int, 0); MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)"); module_param(ticks, int, 0); MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");