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/*
* RDC321x watchdog driver
*
* Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
*
* This driver is highly inspired from the cpu5_wdt driver
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#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/platform_device.h>
#include <linux/watchdog.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/mach-rdc/rdc321x_defs.h>
#define RDC_WDT_MASK 0x80000000 /* Mask */
#define RDC_WDT_EN 0x00800000 /* Enable bit */
#define RDC_WDT_WTI 0x00200000 /* Generate a CPU reset/NMI/WDT irq when WDT timeout is reached */
#define RDC_WDT_RST 0x00100000 /* Reset bit */
#define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
#define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
#define RDC_WDT_CNT 0x00000001 /* WDT count */
#define RDC_CLS_TMR 0x80003844 /* Clear timer */
#define RDC_WDT_INTERVAL (HZ/10+1)
int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int ticks = 1000;
/* some device data */
static struct {
struct completion stop;
volatile int running;
struct timer_list timer;
volatile int queue;
int default_ticks;
unsigned long inuse;
} rdc321x_wdt_device;
/* generic helper functions */
static void rdc321x_wdt_trigger(unsigned long unused)
{
if( rdc321x_wdt_device.running )
ticks--;
/* keep watchdog alive */
outl(RDC_WDT_EN|inl(RDC3210_CFGREG_DATA), RDC3210_CFGREG_DATA);
/* requeue?? */
if (rdc321x_wdt_device.queue && ticks)
mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
else {
/* ticks doesn't matter anyway */
complete(&rdc321x_wdt_device.stop);
}
}
static void rdc321x_wdt_reset(void)
{
ticks = rdc321x_wdt_device.default_ticks;
}
static void rdc321x_wdt_start(void)
{
if (!rdc321x_wdt_device.queue) {
rdc321x_wdt_device.queue = 1;
/* Clear the timer */
outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR);
/* Enable watchdog and set the timeout to 81.92 us */
outl(RDC_WDT_EN|RDC_WDT_CNT, RDC3210_CFGREG_DATA);
mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
}
/* if process dies, counter is not decremented */
rdc321x_wdt_device.running++;
}
static int rdc321x_wdt_stop(void)
{
if (rdc321x_wdt_device.running)
rdc321x_wdt_device.running = 0;
ticks = rdc321x_wdt_device.default_ticks;
return -EIO;
}
/* filesystem operations */
static int rdc321x_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
return -EBUSY;
return nonseekable_open(inode, file);
}
static int rdc321x_wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &rdc321x_wdt_device.inuse);
return 0;
}
static int rdc321x_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 = "RDC321x WDT",
};
switch(cmd) {
case WDIOC_KEEPALIVE:
rdc321x_wdt_reset();
break;
case WDIOC_GETSTATUS:
/* Read the value from the DATA register */
value = inl(RDC3210_CFGREG_DATA);
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:
rdc321x_wdt_start();
break;
case WDIOS_DISABLECARD:
return rdc321x_wdt_stop();
default:
return -EINVAL;
}
break;
default:
return -ENOTTY;
}
return 0;
}
static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
if ( !count )
return -EIO;
rdc321x_wdt_reset();
return count;
}
static const struct file_operations rdc321x_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.ioctl = rdc321x_wdt_ioctl,
.open = rdc321x_wdt_open,
.write = rdc321x_wdt_write,
.release = rdc321x_wdt_release,
};
static struct miscdevice rdc321x_wdt_misc = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &rdc321x_wdt_fops,
};
static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
{
int err;
if ( (err = misc_register(&rdc321x_wdt_misc)) < 0 ) {
printk(KERN_ERR PFX "misc_register failed\n");
return err;
}
/* Reset the watchdog */
outl(RDC_WDT_RST, RDC3210_CFGREG_DATA);
init_completion(&rdc321x_wdt_device.stop);
rdc321x_wdt_device.queue = 0;
clear_bit(0, &rdc321x_wdt_device.inuse);
setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
rdc321x_wdt_device.default_ticks = ticks;
printk(KERN_INFO PFX "init success\n");
return 0;
}
static int rdc321x_wdt_remove(struct platform_device *pdev)
{
if (rdc321x_wdt_device.queue) {
rdc321x_wdt_device.queue = 0;
wait_for_completion(&rdc321x_wdt_device.stop);
}
misc_deregister(&rdc321x_wdt_misc);
return 0;
}
static struct platform_driver rdc321x_wdt_driver = {
.probe = rdc321x_wdt_probe,
.remove = rdc321x_wdt_remove,
.driver = {
.owner = THIS_MODULE,
.name = "rdc321x-wdt",
},
};
static int __init rdc321x_wdt_init(void)
{
return platform_driver_register(&rdc321x_wdt_driver);
}
static void __exit rdc321x_wdt_exit(void)
{
platform_driver_unregister(&rdc321x_wdt_driver);
}
module_init(rdc321x_wdt_init);
module_exit(rdc321x_wdt_exit);
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("RDC321x watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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