/*
* MixCom Watchdog: A Simple Hardware Watchdog Device
* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
*
* Author: Gergely Madarasz <gorgo@itc.hu>
*
* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
*
* 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.
*
* Version 0.1 (99/04/15):
* - first version
*
* Version 0.2 (99/06/16):
* - added kernel timer watchdog ping after close
* since the hardware does not support watchdog shutdown
*
* Version 0.3 (99/06/21):
* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
*
* Version 0.3.1 (99/06/22):
* - allow module removal while internal timer is active,
* print warning about probable reset
*
* Version 0.4 (99/11/15):
* - support for one more type board
*
* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
* - added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
*
*/
#define VERSION "0.5"
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <asm/uaccess.h>
#include <asm/io.h>
static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 };
#define MIXCOM_WATCHDOG_OFFSET 0xc10
#define MIXCOM_ID 0x11
#define FLASHCOM_WATCHDOG_OFFSET 0x4
#define FLASHCOM_ID 0x18
static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
static int watchdog_port;
static int mixcomwd_timer_alive;
static DEFINE_TIMER(mixcomwd_timer, NULL, 0, 0);
static char expect_close;
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
static void mixcomwd_ping(void)
{
outb_p(55,watchdog_port);
return;
}
static void mixcomwd_timerfun(unsigned long d)
{
mixcomwd_ping();
mod_timer(&mixcomwd_timer,jiffies+ 5*HZ);
}
/*
* Allow only one person to hold it open
*/
static int mixcomwd_open(struct inode *inode, struct file *file)
{
if(test_and_set_bit(0,&mixcomwd_opened)) {
return -EBUSY;
}
mixcomwd_ping();
if (nowayout) {
/*
* fops_get() code via open() has already done
* a try_module_get() so it is safe to do the
* __module_get().
*/
__module_get(THIS_MODULE);
} else {
if(mixcomwd_timer_alive) {
del_timer(&mixcomwd_timer);
mixcomwd_timer_alive=0;
}
}
return nonseekable_open(inode, file);
}
static int mixcomwd_release(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
if(mixcomwd_timer_alive) {
printk(KERN_ERR "mixcomwd: release called while internal timer alive");
return -EBUSY;
}
init_timer(&mixcomwd_timer);
mixcomwd_timer.expires=jiffies + 5 * HZ;
mixcomwd_timer.function=mixcomwd_timerfun;
mixcomwd_timer.data=0;
mixcomwd_timer_alive=1;
add_timer(&mixcomwd_timer);
} else {
printk(KERN_CRIT "mixcomwd: WDT device closed unexpectedly. WDT will not stop!\n");
}
clear_bit(0,&mixcomwd_opened);
expect_close=0;
return 0;
}
static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
{
if(len)
{
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
mixcomwd_ping();
}
return len;
}
static int mixcomwd_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int status;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "MixCOM watchdog",
};
switch(cmd)
{
case WDIOC_GETSTATUS:
status=mixcomwd_opened;
if (!nowayout) {
status|=mixcomwd_timer_alive;
}
if (copy_to_user(p, &status, sizeof(int))) {
return -EFAULT;
}
break;
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident))) {
return -EFAULT;
}
break;
case WDIOC_KEEPALIVE:
mixcomwd_ping();
break;
default:
return -ENOTTY;
}
return 0;
}
static const struct file_operations mixcomwd_fops=
{
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mixcomwd_write,
.ioctl = mixcomwd_ioctl,
.open = mixcomwd_open,
.release = mixcomwd_release,
};
static struct miscdevice mixcomwd_miscdev=
{
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mixcomwd_fops,
};
static int __init mixcomwd_checkcard(int port)
{
int id;
port += MIXCOM_WATCHDOG_OFFSET;
if (!request_region(port, 1, "MixCOM watchdog")) {
return 0;
}
id=inb_p(port) & 0x3f;
if(id!=MIXCOM_ID) {
release_region(port, 1);
return 0;
}
return port;
}
static int __init flashcom_checkcard(int port)
{
int id;
port += FLASHCOM_WATCHDOG_OFFSET;
if (!request_region(port, 1, "MixCOM watchdog")) {
return 0;
}
id=inb_p(port);
if(id!=FLASHCOM_ID) {
release_region(port, 1);
return 0;
}
return port;
}
static int __init mixcomwd_init(void)
{
int i;
int ret;
int found=0;
for (i = 0; !found && mixcomwd_ioports[i] != 0; i++) {
watchdog_port = mixcomwd_checkcard(mixcomwd_ioports[i]);
if (watchdog_port) {
found = 1;
}
}
/* The FlashCOM card can be set up at 0x300 -> 0x378, in 0x8 jumps */
for (i = 0x300; !found && i < 0x380; i+=0x8) {
watchdog_port = flashcom_checkcard(i);
if (watchdog_port) {
found = 1;
}
}
if (!found) {
printk("mixcomwd: No card detected, or port not available.\n");
return -ENODEV;
}
ret = misc_register(&mixcomwd_miscdev);
if (ret)
{
release_region(watchdog_port, 1);
return ret;
}
printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);
return 0;
}
static void __exit mixcomwd_exit(void)
{
if (!nowayout) {
if(mixcomwd_timer_alive) {
printk(KERN_WARNING "mixcomwd: I quit now, hardware will"
" probably reboot!\n");
del_timer(&mixcomwd_timer);
mixcomwd_timer_alive=0;
}
}
release_region(watchdog_port,1);
misc_deregister(&mixcomwd_miscdev);
}
module_init(mixcomwd_init);
module_exit(mixcomwd_exit);
MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
MODULE_DESCRIPTION("MixCom Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
