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/*
* Wdt977 0.01: A Watchdog Device for Netwinder W83977AF chip
*
* (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
*
* -----------------------
*
* 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.
*
* -----------------------
*/
#include <linux/module.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#define WATCHDOG_MINOR 130
static int timeout = 3;
static int timer_alive;
static int testmode;
/*
* Allow only one person to hold it open
*/
static int wdt977_open(struct inode *inode, struct file *file)
{
if(timer_alive)
return -EBUSY;
#ifdef CONFIG_WATCHDOG_NOWAYOUT
MOD_INC_USE_COUNT;
#endif
timer_alive++;
//max timeout value = 255 minutes (0xFF). Write 0 to disable WatchDog.
if (timeout>255)
timeout = 255;
printk(KERN_INFO "Watchdog: active, current timeout %d min.\n",timeout);
// unlock the SuperIO chip
outb(0x87,0x370);
outb(0x87,0x370);
//select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
//F2 has the timeout in minutes
//F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
// at timeout, and to reset timer on kbd/mouse activity (not now)
//F4 is used to just clear the TIMEOUT'ed state (bit 0)
outb(0x07,0x370);
outb(0x08,0x371);
outb(0xF2,0x370);
outb(timeout,0x371);
outb(0xF3,0x370);
outb(0x00,0x371); //another setting is 0E for kbd/mouse/LED
outb(0xF4,0x370);
outb(0x00,0x371);
//at last select device Aux1 (dev=7) and set GP16 as a watchdog output
if (!testmode)
{
outb(0x07,0x370);
outb(0x07,0x371);
outb(0xE6,0x370);
outb(0x08,0x371);
}
// lock the SuperIO chip
outb(0xAA,0x370);
return 0;
}
static int wdt977_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
* Lock it in if it's a module and we defined ...NOWAYOUT
*/
#ifndef CONFIG_WATCHDOG_NOWAYOUT
lock_kernel();
// unlock the SuperIO chip
outb(0x87,0x370);
outb(0x87,0x370);
//select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
//F3 is reset to its default state
//F4 can clear the TIMEOUT'ed state (bit 0) - back to default
//We can not use GP17 as a PowerLed, as we use its usage as a RedLed
outb(0x07,0x370);
outb(0x08,0x371);
outb(0xF2,0x370);
outb(0xFF,0x371);
outb(0xF3,0x370);
outb(0x00,0x371);
outb(0xF4,0x370);
outb(0x00,0x371);
outb(0xF2,0x370);
outb(0x00,0x371);
//at last select device Aux1 (dev=7) and set GP16 as a watchdog output
outb(0x07,0x370);
outb(0x07,0x371);
outb(0xE6,0x370);
outb(0x08,0x371);
// lock the SuperIO chip
outb(0xAA,0x370);
timer_alive=0;
unlock_kernel();
printk(KERN_INFO "Watchdog: shutdown.\n");
#endif
return 0;
}
static ssize_t wdt977_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
//max timeout value = 255 minutes (0xFF). Write 0 to disable WatchDog.
if (timeout>255)
timeout = 255;
/*
* Refresh the timer.
*/
//we have a hw bug somewhere, so each 977 minute is actually only 30sec
//as such limit the max timeout to half of max of 255 minutes...
// if (timeout>126)
// timeout = 126;
// unlock the SuperIO chip
outb(0x87,0x370);
outb(0x87,0x370);
//select device Aux2 (device=8) and kicks watchdog reg F2
//F2 has the timeout in minutes
outb(0x07,0x370);
outb(0x08,0x371);
outb(0xF2,0x370);
outb(timeout,0x371);
// lock the SuperIO chip
outb(0xAA,0x370);
return 1;
}
static struct file_operations wdt977_fops=
{
owner: THIS_MODULE,
write: wdt977_write,
open: wdt977_open,
release: wdt977_release,
};
static struct miscdevice wdt977_miscdev=
{
WATCHDOG_MINOR,
"watchdog",
&wdt977_fops
};
static int __init nwwatchdog_init(void)
{
if (!machine_is_netwinder())
return -ENODEV;
misc_register(&wdt977_miscdev);
printk(KERN_INFO "NetWinder Watchdog sleeping.\n");
return 0;
}
static void __exit nwwatchdog_exit(void)
{
misc_deregister(&wdt977_miscdev);
}
EXPORT_NO_SYMBOLS;
module_init(nwwatchdog_init);
module_exit(nwwatchdog_exit);
MODULE_LICENSE("GPL");
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