326 lines
7.1 KiB
C
326 lines
7.1 KiB
C
/*
|
|
* ICP Wafer 5823 Single Board Computer WDT driver
|
|
* http://www.icpamerica.com/wafer_5823.php
|
|
* May also work on other similar models
|
|
*
|
|
* (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
|
|
*
|
|
* Release 0.02
|
|
*
|
|
* Based on advantechwdt.c which is based on wdt.c.
|
|
* Original copyright messages:
|
|
*
|
|
* (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
|
|
* All Rights Reserved.
|
|
*
|
|
* 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.
|
|
*
|
|
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
|
|
* warranty for any of this software. This material is provided
|
|
* "AS-IS" and at no charge.
|
|
*
|
|
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
|
|
*
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/init.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/io.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#define WATCHDOG_NAME "Wafer 5823 WDT"
|
|
#define PFX WATCHDOG_NAME ": "
|
|
#define WD_TIMO 60 /* 60 sec default timeout */
|
|
|
|
static unsigned long wafwdt_is_open;
|
|
static char expect_close;
|
|
static DEFINE_SPINLOCK(wafwdt_lock);
|
|
|
|
/*
|
|
* You must set these - there is no sane way to probe for this board.
|
|
*
|
|
* To enable, write the timeout value in seconds (1 to 255) to I/O
|
|
* port WDT_START, then read the port to start the watchdog. To pat
|
|
* the dog, read port WDT_STOP to stop the timer, then read WDT_START
|
|
* to restart it again.
|
|
*/
|
|
|
|
static int wdt_stop = 0x843;
|
|
static int wdt_start = 0x443;
|
|
|
|
static int timeout = WD_TIMO; /* in seconds */
|
|
module_param(timeout, int, 0);
|
|
MODULE_PARM_DESC(timeout,
|
|
"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
|
|
__MODULE_STRING(WD_TIMO) ".");
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
static void wafwdt_ping(void)
|
|
{
|
|
/* pat watchdog */
|
|
spin_lock(&wafwdt_lock);
|
|
inb_p(wdt_stop);
|
|
inb_p(wdt_start);
|
|
spin_unlock(&wafwdt_lock);
|
|
}
|
|
|
|
static void wafwdt_start(void)
|
|
{
|
|
/* start up watchdog */
|
|
outb_p(timeout, wdt_start);
|
|
inb_p(wdt_start);
|
|
}
|
|
|
|
static void wafwdt_stop(void)
|
|
{
|
|
/* stop watchdog */
|
|
inb_p(wdt_stop);
|
|
}
|
|
|
|
static ssize_t wafwdt_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
/* See if we got the magic character 'V' and reload the timer */
|
|
if (count) {
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
/* In case it was set long ago */
|
|
expect_close = 0;
|
|
|
|
/* scan to see whether or not we got the magic
|
|
character */
|
|
for (i = 0; i != count; i++) {
|
|
char c;
|
|
if (get_user(c, buf + i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
expect_close = 42;
|
|
}
|
|
}
|
|
/* Well, anyhow someone wrote to us, we should
|
|
return that favour */
|
|
wafwdt_ping();
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static long wafwdt_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int new_timeout;
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
static const struct watchdog_info ident = {
|
|
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
|
|
WDIOF_MAGICCLOSE,
|
|
.firmware_version = 1,
|
|
.identity = "Wafer 5823 WDT",
|
|
};
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
if (copy_to_user(argp, &ident, sizeof(ident)))
|
|
return -EFAULT;
|
|
break;
|
|
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, p);
|
|
|
|
case WDIOC_SETOPTIONS:
|
|
{
|
|
int options, retval = -EINVAL;
|
|
|
|
if (get_user(options, p))
|
|
return -EFAULT;
|
|
|
|
if (options & WDIOS_DISABLECARD) {
|
|
wafwdt_stop();
|
|
retval = 0;
|
|
}
|
|
|
|
if (options & WDIOS_ENABLECARD) {
|
|
wafwdt_start();
|
|
retval = 0;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
case WDIOC_KEEPALIVE:
|
|
wafwdt_ping();
|
|
break;
|
|
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_timeout, p))
|
|
return -EFAULT;
|
|
if ((new_timeout < 1) || (new_timeout > 255))
|
|
return -EINVAL;
|
|
timeout = new_timeout;
|
|
wafwdt_stop();
|
|
wafwdt_start();
|
|
/* Fall */
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(timeout, p);
|
|
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int wafwdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_and_set_bit(0, &wafwdt_is_open))
|
|
return -EBUSY;
|
|
|
|
/*
|
|
* Activate
|
|
*/
|
|
wafwdt_start();
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int wafwdt_close(struct inode *inode, struct file *file)
|
|
{
|
|
if (expect_close == 42)
|
|
wafwdt_stop();
|
|
else {
|
|
pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
|
|
wafwdt_ping();
|
|
}
|
|
clear_bit(0, &wafwdt_is_open);
|
|
expect_close = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Notifier for system down
|
|
*/
|
|
|
|
static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
|
|
void *unused)
|
|
{
|
|
if (code == SYS_DOWN || code == SYS_HALT)
|
|
wafwdt_stop();
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/*
|
|
* Kernel Interfaces
|
|
*/
|
|
|
|
static const struct file_operations wafwdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = wafwdt_write,
|
|
.unlocked_ioctl = wafwdt_ioctl,
|
|
.open = wafwdt_open,
|
|
.release = wafwdt_close,
|
|
};
|
|
|
|
static struct miscdevice wafwdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &wafwdt_fops,
|
|
};
|
|
|
|
/*
|
|
* The WDT needs to learn about soft shutdowns in order to
|
|
* turn the timebomb registers off.
|
|
*/
|
|
|
|
static struct notifier_block wafwdt_notifier = {
|
|
.notifier_call = wafwdt_notify_sys,
|
|
};
|
|
|
|
static int __init wafwdt_init(void)
|
|
{
|
|
int ret;
|
|
|
|
pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
|
|
|
|
if (timeout < 1 || timeout > 255) {
|
|
timeout = WD_TIMO;
|
|
pr_info("timeout value must be 1 <= x <= 255, using %d\n",
|
|
timeout);
|
|
}
|
|
|
|
if (wdt_stop != wdt_start) {
|
|
if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
|
|
pr_err("I/O address 0x%04x already in use\n", wdt_stop);
|
|
ret = -EIO;
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
|
|
pr_err("I/O address 0x%04x already in use\n", wdt_start);
|
|
ret = -EIO;
|
|
goto error2;
|
|
}
|
|
|
|
ret = register_reboot_notifier(&wafwdt_notifier);
|
|
if (ret != 0) {
|
|
pr_err("cannot register reboot notifier (err=%d)\n", ret);
|
|
goto error3;
|
|
}
|
|
|
|
ret = misc_register(&wafwdt_miscdev);
|
|
if (ret != 0) {
|
|
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
|
|
WATCHDOG_MINOR, ret);
|
|
goto error4;
|
|
}
|
|
|
|
pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
|
|
timeout, nowayout);
|
|
|
|
return ret;
|
|
error4:
|
|
unregister_reboot_notifier(&wafwdt_notifier);
|
|
error3:
|
|
release_region(wdt_start, 1);
|
|
error2:
|
|
if (wdt_stop != wdt_start)
|
|
release_region(wdt_stop, 1);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit wafwdt_exit(void)
|
|
{
|
|
misc_deregister(&wafwdt_miscdev);
|
|
unregister_reboot_notifier(&wafwdt_notifier);
|
|
if (wdt_stop != wdt_start)
|
|
release_region(wdt_stop, 1);
|
|
release_region(wdt_start, 1);
|
|
}
|
|
|
|
module_init(wafwdt_init);
|
|
module_exit(wafwdt_exit);
|
|
|
|
MODULE_AUTHOR("Justin Cormack");
|
|
MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
/* end of wafer5823wdt.c */
|