diff options
Diffstat (limited to 'drivers/char/watchdog/cpu5wdt.c')
| -rw-r--r-- | drivers/char/watchdog/cpu5wdt.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/drivers/char/watchdog/cpu5wdt.c b/drivers/char/watchdog/cpu5wdt.c new file mode 100644 index 000000000000..2865dac0a813 --- /dev/null +++ b/drivers/char/watchdog/cpu5wdt.c @@ -0,0 +1,303 @@ +/* + * 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 <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 semaphore 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 ) { + cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL; + add_timer(&cpu5wdt_device.timer); + } + else { + /* ticks doesn't matter anyway */ + up(&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); + cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL; + add_timer(&cpu5wdt_device.timer); + } + /* 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_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 -ENOIOCTLCMD; + } + 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 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 ( (err = misc_register(&cpu5wdt_misc)) < 0 ) { + printk(KERN_ERR PFX "misc_register failed\n"); + goto no_misc; + } + + 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"); + + init_MUTEX_LOCKED(&cpu5wdt_device.stop); + cpu5wdt_device.queue = 0; + + clear_bit(0, &cpu5wdt_device.inuse); + + init_timer(&cpu5wdt_device.timer); + cpu5wdt_device.timer.function = cpu5wdt_trigger; + cpu5wdt_device.timer.data = 0; + + cpu5wdt_device.default_ticks = ticks; + + printk(KERN_INFO PFX "init success\n"); + + return 0; + +no_port: + misc_deregister(&cpu5wdt_misc); +no_misc: + 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; + down(&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"); |