|  | /* | 
|  | * 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 <asm/io.h> | 
|  | #include <asm/uaccess.h> | 
|  |  | 
|  | #include <linux/watchdog.h> | 
|  |  | 
|  | /* adjustable parameters */ | 
|  |  | 
|  | static int verbose = 0; | 
|  | static int port = 0x91; | 
|  | static int ticks = 10000; | 
|  |  | 
|  | #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; | 
|  | volatile int running; | 
|  | struct timer_list timer; | 
|  | volatile 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--; | 
|  |  | 
|  | /* 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); | 
|  | } | 
|  |  | 
|  | } | 
|  |  | 
|  | 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) | 
|  | { | 
|  | 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++; | 
|  | } | 
|  |  | 
|  | static int cpu5wdt_stop(void) | 
|  | { | 
|  | if ( cpu5wdt_device.running ) | 
|  | cpu5wdt_device.running = 0; | 
|  |  | 
|  | ticks = cpu5wdt_device.default_ticks; | 
|  |  | 
|  | 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 int cpu5wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | 
|  | { | 
|  | void __user *argp = (void __user *)arg; | 
|  | unsigned int value; | 
|  | static struct watchdog_info ident = | 
|  | { | 
|  | .options = WDIOF_CARDRESET, | 
|  | .identity = "CPU5 WDT", | 
|  | }; | 
|  |  | 
|  | switch(cmd) { | 
|  | case WDIOC_KEEPALIVE: | 
|  | cpu5wdt_reset(); | 
|  | break; | 
|  | case WDIOC_GETSTATUS: | 
|  | value = inb(port + CPU5WDT_STATUS_REG); | 
|  | value = (value >> 2) & 1; | 
|  | if ( copy_to_user(argp, &value, sizeof(int)) ) | 
|  | return -EFAULT; | 
|  | break; | 
|  | case WDIOC_GETBOOTSTATUS: | 
|  | if ( copy_to_user(argp, &value, sizeof(int)) ) | 
|  | return -EFAULT; | 
|  | break; | 
|  | case WDIOC_GETSUPPORT: | 
|  | if ( copy_to_user(argp, &ident, sizeof(ident)) ) | 
|  | return -EFAULT; | 
|  | break; | 
|  | case WDIOC_SETOPTIONS: | 
|  | if ( copy_from_user(&value, argp, sizeof(int)) ) | 
|  | return -EFAULT; | 
|  | switch(value) { | 
|  | case WDIOS_ENABLECARD: | 
|  | cpu5wdt_start(); | 
|  | break; | 
|  | case WDIOS_DISABLECARD: | 
|  | return cpu5wdt_stop(); | 
|  | default: | 
|  | return -EINVAL; | 
|  | } | 
|  | 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, | 
|  | .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); | 
|  |  | 
|  | if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) { | 
|  | printk(KERN_ERR PFX "request_region failed\n"); | 
|  | err = -EBUSY; | 
|  | goto no_port; | 
|  | } | 
|  |  | 
|  | if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) { | 
|  | printk(KERN_ERR PFX "misc_register failed\n"); | 
|  | goto no_misc; | 
|  | } | 
|  |  | 
|  | /* watchdog reboot? */ | 
|  | val = inb(port + CPU5WDT_STATUS_REG); | 
|  | val = (val >> 2) & 1; | 
|  | if ( !val ) | 
|  | printk(KERN_INFO PFX "sorry, was my fault\n"); | 
|  |  | 
|  | init_completion(&cpu5wdt_device.stop); | 
|  | cpu5wdt_device.queue = 0; | 
|  |  | 
|  | clear_bit(0, &cpu5wdt_device.inuse); | 
|  |  | 
|  | setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0); | 
|  |  | 
|  | cpu5wdt_device.default_ticks = ticks; | 
|  |  | 
|  | 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"); |