linux/drivers/watchdog/mpc8xx_wdt.c
Alan Cox f26ef3dc69 [WATCHDOG 26/57] mpc watchdog: clean up and locking
Review and switch to unlocked_ioctl

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-06-13 19:44:39 +00:00

170 lines
3.7 KiB
C

/*
* mpc8xx_wdt.c - MPC8xx watchdog userspace interface
*
* Author: Florian Schirmer <jolt@tuxbox.org>
*
* 2002 (c) Florian Schirmer <jolt@tuxbox.org> 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/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <asm/8xx_immap.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <syslib/m8xx_wdt.h>
static unsigned long wdt_opened;
static int wdt_status;
static spinlock_t wdt_lock;
static void mpc8xx_wdt_handler_disable(void)
{
volatile uint __iomem *piscr;
piscr = (uint *)&((immap_t *)IMAP_ADDR)->im_sit.sit_piscr;
if (!m8xx_has_internal_rtc)
m8xx_wdt_stop_timer();
else
out_be32(piscr, in_be32(piscr) & ~(PISCR_PIE | PISCR_PTE));
printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
}
static void mpc8xx_wdt_handler_enable(void)
{
volatile uint __iomem *piscr;
piscr = (uint *)&((immap_t *)IMAP_ADDR)->im_sit.sit_piscr;
if (!m8xx_has_internal_rtc)
m8xx_wdt_install_timer();
else
out_be32(piscr, in_be32(piscr) | PISCR_PIE | PISCR_PTE);
printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
}
static int mpc8xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &wdt_opened))
return -EBUSY;
m8xx_wdt_reset();
mpc8xx_wdt_handler_disable();
return nonseekable_open(inode, file);
}
static int mpc8xx_wdt_release(struct inode *inode, struct file *file)
{
m8xx_wdt_reset();
#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
mpc8xx_wdt_handler_enable();
#endif
clear_bit(0, &wdt_opened);
return 0;
}
static ssize_t mpc8xx_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
if (len) {
spin_lock(&wdt_lock);
m8xx_wdt_reset();
spin_unlock(&wdt_lock);
}
return len;
}
static long mpc8xx_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
int timeout;
static struct watchdog_info info = {
.options = WDIOF_KEEPALIVEPING,
.firmware_version = 0,
.identity = "MPC8xx watchdog",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user((void *)arg, &info, sizeof(info)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
if (put_user(wdt_status, (int *)arg))
return -EFAULT;
wdt_status &= ~WDIOF_KEEPALIVEPING;
break;
case WDIOC_GETTEMP:
return -EOPNOTSUPP;
case WDIOC_SETOPTIONS:
return -EOPNOTSUPP;
case WDIOC_KEEPALIVE:
spin_lock(&wdt_lock);
m8xx_wdt_reset();
wdt_status |= WDIOF_KEEPALIVEPING;
spin_unlock(&wdt_lock);
break;
case WDIOC_SETTIMEOUT:
return -EOPNOTSUPP;
case WDIOC_GETTIMEOUT:
spin_lock(&wdt_lock);
timeout = m8xx_wdt_get_timeout();
spin_unlock(&wdt_lock);
if (put_user(timeout, (int *)arg))
return -EFAULT;
break;
default:
return -ENOTTY;
}
return 0;
}
static const struct file_operations mpc8xx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mpc8xx_wdt_write,
.unlocked_ioctl = mpc8xx_wdt_ioctl,
.open = mpc8xx_wdt_open,
.release = mpc8xx_wdt_release,
};
static struct miscdevice mpc8xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mpc8xx_wdt_fops,
};
static int __init mpc8xx_wdt_init(void)
{
spin_lock_init(&wdt_lock);
return misc_register(&mpc8xx_wdt_miscdev);
}
static void __exit mpc8xx_wdt_exit(void)
{
misc_deregister(&mpc8xx_wdt_miscdev);
m8xx_wdt_reset();
mpc8xx_wdt_handler_enable();
}
module_init(mpc8xx_wdt_init);
module_exit(mpc8xx_wdt_exit);
MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
MODULE_DESCRIPTION("MPC8xx watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);