openwrt/target/linux/atheros/files/drivers/watchdog/ar2315-wtd.c

199 lines
4.4 KiB
C

/*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright (C) 2008 John Crispin <blogic@openwrt.org>
* Based on EP93xx and ifxmips wdt driver
*/
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.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/platform_device.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/addrspace.h>
#include <ar531x.h>
#define CLOCK_RATE 40000000
#define HEARTBEAT(x) (x < 1 || x > 90)?(20):(x)
static int wdt_timeout = 20;
static int started = 0;
static int in_use = 0;
static void
ar2315_wdt_enable(void)
{
sysRegWrite(AR5315_WD, wdt_timeout * CLOCK_RATE);
sysRegWrite(AR5315_ISR, 0x80);
}
static ssize_t
ar2315_wdt_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
{
if(len)
ar2315_wdt_enable();
return len;
}
static int
ar2315_wdt_open(struct inode *inode, struct file *file)
{
if(in_use)
return -EBUSY;
ar2315_wdt_enable();
in_use = started = 1;
return nonseekable_open(inode, file);
}
static int
ar2315_wdt_release(struct inode *inode, struct file *file)
{
in_use = 0;
return 0;
}
static irqreturn_t
ar2315_wdt_interrupt(int irq, void *dev_id)
{
if(started)
{
printk(KERN_CRIT "watchdog expired, rebooting system\n");
sysRegWrite(AR5315_COLD_RESET, RESET_SYSTEM);
} else {
sysRegWrite(AR5315_WDC, 0);
sysRegWrite(AR5315_WD, 0);
sysRegWrite(AR5315_ISR, 0x80);
}
return IRQ_HANDLED;
}
static struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "ar2315 Watchdog",
};
static int
ar2315_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
int new_wdt_timeout;
int ret = -ENOIOCTLCMD;
switch(cmd)
{
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info __user *)arg, &ident, sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_KEEPALIVE:
ar2315_wdt_enable();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
if((ret = get_user(new_wdt_timeout, (int __user *)arg)))
break;
wdt_timeout = HEARTBEAT(new_wdt_timeout);
ar2315_wdt_enable();
break;
case WDIOC_GETTIMEOUT:
ret = put_user(wdt_timeout, (int __user *)arg);
break;
}
return ret;
}
static struct file_operations ar2315_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = ar2315_wdt_write,
.ioctl = ar2315_wdt_ioctl,
.open = ar2315_wdt_open,
.release = ar2315_wdt_release,
};
static struct miscdevice ar2315_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ar2315_wdt_fops,
};
static int
ar2315_wdt_probe(struct platform_device *dev)
{
int ret = 0;
ar2315_wdt_enable();
ret = request_irq(AR531X_MISC_IRQ_WATCHDOG, ar2315_wdt_interrupt, IRQF_DISABLED, "ar2315_wdt", NULL);
if(ret)
{
printk(KERN_ERR "ar2315wdt: failed to register inetrrupt\n");
goto out;
}
ret = misc_register(&ar2315_wdt_miscdev);
if(ret)
printk(KERN_ERR "ar2315wdt: failed to register miscdev\n");
out:
return ret;
}
static int
ar2315_wdt_remove(struct platform_device *dev)
{
misc_deregister(&ar2315_wdt_miscdev);
free_irq(AR531X_MISC_IRQ_WATCHDOG, NULL);
return 0;
}
static struct platform_driver ar2315_wdt_driver = {
.probe = ar2315_wdt_probe,
.remove = ar2315_wdt_remove,
.driver = {
.name = "ar2315_wdt",
.owner = THIS_MODULE,
},
};
static int __init
init_ar2315_wdt(void)
{
int ret = platform_driver_register(&ar2315_wdt_driver);
if(ret)
printk(KERN_INFO "ar2315_wdt: error registering platfom driver!");
return ret;
}
static void __exit
exit_ar2315_wdt(void)
{
platform_driver_unregister(&ar2315_wdt_driver);
}
module_init(init_ar2315_wdt);
module_exit(exit_ar2315_wdt);