/*
* 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/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 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");
