OpenWrt – Rev 2
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/*
* avila-wdt.c
* Copyright (C) 2009 Felix Fietkau <nbd@nbd.name>
*
* based on:
* drivers/char/watchdog/ixp4xx_wdt.c
*
* Watchdog driver for Intel IXP4xx network processors
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2004 (c) MontaVista, Software, Inc.
* Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/uaccess.h>
#include <mach/hardware.h>
static int nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = 20; /* (secs) Default is 20 seconds */
static unsigned long wdt_status;
static atomic_t wdt_counter;
struct timer_list wdt_timer;
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
#define WDT_RUNNING 2
static void wdt_refresh(unsigned long data)
{
if (test_bit(WDT_RUNNING, &wdt_status)) {
if (atomic_dec_and_test(&wdt_counter)) {
printk(KERN_WARNING "Avila watchdog expired, expect a reboot soon!\n");
clear_bit(WDT_RUNNING, &wdt_status);
return;
}
}
/* strobe to the watchdog */
gpio_line_set(14, IXP4XX_GPIO_HIGH);
gpio_line_set(14, IXP4XX_GPIO_LOW);
mod_timer(&wdt_timer, jiffies + msecs_to_jiffies(500));
}
static void wdt_enable(void)
{
atomic_set(&wdt_counter, heartbeat * 2);
/* Disable clock generator output on GPIO 14/15 */
*IXP4XX_GPIO_GPCLKR &= ~(1 << 8);
/* activate GPIO 14 out */
gpio_line_config(14, IXP4XX_GPIO_OUT);
gpio_line_set(14, IXP4XX_GPIO_LOW);
if (!test_bit(WDT_RUNNING, &wdt_status))
wdt_refresh(0);
set_bit(WDT_RUNNING, &wdt_status);
}
static void wdt_disable(void)
{
/* Re-enable clock generator output on GPIO 14/15 */
*IXP4XX_GPIO_GPCLKR |= (1 << 8);
}
static int avila_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
wdt_enable();
return nonseekable_open(inode, file);
}
static ssize_t
avila_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
}
wdt_enable();
}
return len;
}
static struct watchdog_info ident = {
.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "Avila Watchdog",
};
static long avila_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
int time;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_KEEPALIVE:
wdt_enable();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, (int *)arg);
if (ret)
break;
if (time <= 0 || time > 60) {
ret = -EINVAL;
break;
}
heartbeat = time;
wdt_enable();
/* Fall through */
case WDIOC_GETTIMEOUT:
ret = put_user(heartbeat, (int *)arg);
break;
}
return ret;
}
static int avila_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
wdt_disable();
else
printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
"timer will not stop\n");
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
return 0;
}
static const struct file_operations avila_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = avila_wdt_write,
.unlocked_ioctl = avila_wdt_ioctl,
.open = avila_wdt_open,
.release = avila_wdt_release,
};
static struct miscdevice avila_wdt_miscdev = {
.minor = WATCHDOG_MINOR + 1,
.name = "avila_watchdog",
.fops = &avila_wdt_fops,
};
static int __init avila_wdt_init(void)
{
int ret;
init_timer(&wdt_timer);
wdt_timer.expires = 0;
wdt_timer.data = 0;
wdt_timer.function = wdt_refresh;
ret = misc_register(&avila_wdt_miscdev);
if (ret == 0)
printk(KERN_INFO "Avila Watchdog Timer: heartbeat %d sec\n",
heartbeat);
return ret;
}
static void __exit avila_wdt_exit(void)
{
misc_deregister(&avila_wdt_miscdev);
del_timer(&wdt_timer);
wdt_disable();
}
module_init(avila_wdt_init);
module_exit(avila_wdt_exit);
MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
MODULE_DESCRIPTION("Gateworks Avila Hardware Watchdog");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 20s)");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);