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/*
* Driver for the MTX-1 Watchdog.
*
* (C) Copyright 2005 4G Systems <info@4g-systems.biz>, All Rights Reserved.
* http://www.4g-systems.biz
*
* (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.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.
*
* Neither Michael Stickel nor 4G Systems admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 2005 4G Systems <info@4g-systems.biz>
*
* Release 0.01.
* Author: Michael Stickel michael.stickel@4g-systems.biz
*
* Release 0.02.
* Author: Florian Fainelli florian@openwrt.org
* use the Linux watchdog/timer APIs
*
* The Watchdog is configured to reset the MTX-1
* if it is not triggered for 100 seconds.
* It should not be triggered more often than 1.6 seconds.
*
* A timer triggers the watchdog every 5 seconds, until
* it is opened for the first time. After the first open
* it MUST be triggered every 2..95 seconds.
*/
#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/completion.h>
#include <linux/jiffies.h>
#include <linux/watchdog.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/mach-au1x00/au1000.h>
#define MTX1_WDT_INTERVAL (5 * HZ)
static int ticks = 100 * HZ;
static struct {
struct completion stop;
volatile int running;
struct timer_list timer;
volatile int queue;
int default_ticks;
unsigned long inuse;
} mtx1_wdt_device;
static void mtx1_wdt_trigger(unsigned long unused)
{
u32 tmp;
if (mtx1_wdt_device.running)
ticks--;
/*
* toggle GPIO2_15
*/
tmp = au_readl(GPIO2_DIR);
tmp = (tmp & ~(1<<15)) | ((~tmp) & (1<<15));
au_writel (tmp, GPIO2_DIR);
if (mtx1_wdt_device.queue && ticks)
mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
else {
complete(&mtx1_wdt_device.stop);
}
}
static void mtx1_wdt_reset(void)
{
ticks = mtx1_wdt_device.default_ticks;
}
static void mtx1_wdt_start(void)
{
if (!mtx1_wdt_device.queue) {
mtx1_wdt_device.queue = 1;
au_writel (au_readl(GPIO2_DIR) | (u32)(1<<15), GPIO2_DIR);
mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
}
mtx1_wdt_device.running++;
}
static int mtx1_wdt_stop(void)
{
if (mtx1_wdt_device.queue) {
mtx1_wdt_device.queue = 0;
au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR);
}
ticks = mtx1_wdt_device.default_ticks;
return 0;
}
/* Filesystem functions */
static int mtx1_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
return -EBUSY;
return nonseekable_open(inode, file);
}
static int mtx1_wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &mtx1_wdt_device.inuse);
return 0;
}
static int mtx1_wdt_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 = "MTX-1 WDT",
};
switch(cmd) {
case WDIOC_KEEPALIVE:
mtx1_wdt_reset();
break;
case WDIOC_GETSTATUS:
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:
mtx1_wdt_start();
break;
case WDIOS_DISABLECARD:
return mtx1_wdt_stop();
default:
return -EINVAL;
}
break;
default:
return -ENOTTY;
}
return 0;
}
static ssize_t mtx1_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
{
if (!count)
return -EIO;
mtx1_wdt_reset();
return count;
}
static struct file_operations mtx1_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.ioctl = mtx1_wdt_ioctl,
.open = mtx1_wdt_open,
.write = mtx1_wdt_write,
.release = mtx1_wdt_release
};
static struct miscdevice mtx1_wdt_misc = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mtx1_wdt_fops
};
static int __init mtx1_wdt_init(void)
{
int ret;
if ((ret = misc_register(&mtx1_wdt_misc)) < 0) {
printk(KERN_ERR " mtx-1_wdt : failed to register\n");
return ret;
}
init_completion(&mtx1_wdt_device.stop);
mtx1_wdt_device.queue = 0;
clear_bit(0, &mtx1_wdt_device.inuse);
setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
mtx1_wdt_device.default_ticks = ticks;
mtx1_wdt_start();
printk(KERN_INFO "MTX-1 Watchdog driver\n");
return 0;
}
static void __exit mtx1_wdt_exit(void)
{
if (mtx1_wdt_device.queue) {
mtx1_wdt_device.queue = 0;
wait_for_completion(&mtx1_wdt_device.stop);
}
misc_deregister(&mtx1_wdt_misc);
}
module_init(mtx1_wdt_init);
module_exit(mtx1_wdt_exit);
MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
MODULE_LICENSE("GPL");
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