openwrt/target/linux/rdc/files-2.6.30/drivers/watchdog/rdc321x_wdt.c

287 lines
6.5 KiB
C

/*
* RDC321x watchdog driver
*
* Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
*
* 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/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <asm/rdc321x_defs.h>
extern int rdc321x_pci_write(int reg, u32 val);
extern int rdc321x_pci_read(int reg, u32 *val);
#define RDC321X_WDT_REG 0x00000044
#define RDC_WDT_EN 0x00800000 /* Enable bit */
#define RDC_WDT_WDTIRQ 0x00400000 /* Create WDT IRQ before CPU reset */
#define RDC_WDT_NMIIRQ 0x00200000 /* Create NMI IRQ before CPU reset */
#define RDC_WDT_RST 0x00100000 /* Reset wdt */
#define RDC_WDT_NIF 0x00080000 /* NMI interrupt occured */
#define RDC_WDT_WIF 0x00040000 /* WDT interrupt occured */
#define RDC_WDT_IRT 0x00000700 /* IRQ Routing table */
#define RDC_WDT_CNT 0x0000007F /* WDT count */
/* default counter value (2.34 s) */
#define RDC_WDT_DFLT_CNT 0x00000040
#define RDC_WDT_SETUP (RDC_WDT_EN | RDC_WDT_NMIIRQ | RDC_WDT_RST | RDC_WDT_DFLT_CNT)
/* some device data */
static struct {
struct timer_list timer;
int seconds_left;
int total_seconds;
bool inuse;
bool running;
bool close_expected;
} rdc321x_wdt_dev;
static struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.identity = "RDC321x WDT",
};
/* generic helper functions */
static void rdc321x_wdt_timer(unsigned long unused)
{
if (!rdc321x_wdt_dev.running) {
rdc321x_pci_write(RDC321X_WDT_REG, 0);
return;
}
rdc321x_wdt_dev.seconds_left--;
if (rdc321x_wdt_dev.seconds_left < 1)
return;
rdc321x_pci_write(RDC321X_WDT_REG, RDC_WDT_SETUP);
mod_timer(&rdc321x_wdt_dev.timer, HZ * 2 + jiffies);
}
static void rdc321x_wdt_reset(void)
{
rdc321x_wdt_dev.seconds_left = rdc321x_wdt_dev.total_seconds;
}
static void rdc321x_wdt_start(void)
{
if (rdc321x_wdt_dev.running)
return;
rdc321x_wdt_dev.seconds_left = rdc321x_wdt_dev.total_seconds;
rdc321x_wdt_dev.running = true;
rdc321x_wdt_timer(0);
return;
}
static int rdc321x_wdt_stop(void)
{
if (WATCHDOG_NOWAYOUT)
return -ENOSYS;
rdc321x_wdt_dev.running = false;
return 0;
}
/* filesystem operations */
static int rdc321x_wdt_open(struct inode *inode, struct file *file)
{
if (xchg(&rdc321x_wdt_dev.inuse, true))
return -EBUSY;
return nonseekable_open(inode, file);
}
static int rdc321x_wdt_release(struct inode *inode, struct file *file)
{
int res;
if (rdc321x_wdt_dev.close_expected) {
res = rdc321x_wdt_stop();
if (res)
return res;
}
rdc321x_wdt_dev.inuse = false;
return 0;
}
static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int value;
switch (cmd) {
case WDIOC_KEEPALIVE:
rdc321x_wdt_reset();
break;
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_SETTIMEOUT:
if (copy_from_user(&rdc321x_wdt_dev.total_seconds, argp, sizeof(int)))
return -EFAULT;
rdc321x_wdt_dev.seconds_left = rdc321x_wdt_dev.total_seconds;
break;
case WDIOC_GETTIMEOUT:
if (copy_to_user(argp, &rdc321x_wdt_dev.total_seconds, sizeof(int)))
return -EFAULT;
break;
case WDIOC_GETTIMELEFT:
if (copy_to_user(argp, &rdc321x_wdt_dev.seconds_left, sizeof(int)))
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 -EINVAL;
}
return 0;
}
static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
size_t i;
if (!count)
return -EIO;
rdc321x_wdt_dev.close_expected = false;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V') {
rdc321x_wdt_dev.close_expected = true;
break;
}
}
rdc321x_wdt_reset();
return count;
}
static const struct file_operations rdc321x_wdt_fops = {
.llseek = no_llseek,
.unlocked_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 __init rdc321x_wdt_probe(struct platform_device *pdev)
{
int err;
err = rdc321x_pci_write(RDC321X_WDT_REG, 0);
if (err)
return err;
rdc321x_wdt_dev.running = false;
rdc321x_wdt_dev.close_expected = false;
rdc321x_wdt_dev.inuse = 0;
setup_timer(&rdc321x_wdt_dev.timer, rdc321x_wdt_timer, 0);
rdc321x_wdt_dev.total_seconds = 100;
err = misc_register(&rdc321x_wdt_misc);
if (err < 0) {
printk(KERN_ERR PFX "watchdog: misc_register failed\n");
return err;
}
dev_info(&pdev->dev, "watchdog init success\n");
return 0;
}
static int __devexit rdc321x_wdt_remove(struct platform_device *pdev)
{
if (rdc321x_wdt_dev.inuse)
rdc321x_wdt_dev.inuse = 0;
while (timer_pending(&rdc321x_wdt_dev.timer))
msleep(100);
misc_deregister(&rdc321x_wdt_misc);
return 0;
}
static struct platform_driver rdc321x_wdt_driver = {
.driver.name = "rdc321x-wdt",
.driver.owner = THIS_MODULE,
.probe = rdc321x_wdt_probe,
.remove = __devexit_p(rdc321x_wdt_remove),
};
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("platform:rdc321x-wdt");