openwrt/target/linux/aruba-2.6/files/drivers/char/watchdog/wdt_merlot.c

113 lines
2.3 KiB
C

#include <linux/autoconf.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bootinfo.h>
extern unsigned long mips_machtype;
static unsigned long wdt_is_open;
static struct timer_list wdt_timer;
static void wdt_merlot_refresh(void)
{
volatile __u32 *wdt;
switch (mips_machtype) {
case MACH_ARUBA_AP70:
wdt = (__u32 *) 0xb8030034;
*wdt = 0x10000000;
break;
default:
wdt = (__u32 *) 0xbc00300c;
*wdt = 0x40000000;
break;
}
}
static void wdt_merlot_timer_fn(unsigned long data)
{
wdt_merlot_refresh();
if (!test_bit(1, &wdt_is_open))
mod_timer(&wdt_timer, jiffies + HZ);
}
static int wdt_merlot_setup_timer(void)
{
init_timer(&wdt_timer);
wdt_timer.function = wdt_merlot_timer_fn;
wdt_timer.data = 0;
wdt_timer.expires = jiffies + HZ;
add_timer(&wdt_timer);
return 0;
}
static int wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &wdt_is_open))
return -EBUSY;
set_bit(1, &wdt_is_open);
return nonseekable_open(inode, file);
}
static ssize_t wdt_write(struct file *file, const char __user * buf, size_t count, loff_t * ppos)
{
if (count) /* something was written */
wdt_merlot_refresh();
return count;
}
static int wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &wdt_is_open);
return 0;
}
static struct file_operations wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdt_write,
.open = wdt_open,
.release = wdt_release,
};
static struct miscdevice wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdt_fops,
};
static void __exit wdt_exit(void)
{
misc_deregister(&wdt_miscdev);
}
static int __init wdt_init(void)
{
int ret;
ret = misc_register(&wdt_miscdev);
if (ret) {
printk(KERN_ERR
"wdt: cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
misc_deregister(&wdt_miscdev);
goto out;
}
printk("wdt: registered with refresh\n");
wdt_merlot_refresh();
wdt_merlot_setup_timer();
out:
return ret;
}
module_init(wdt_init);
module_exit(wdt_exit);