273 lines
6.4 KiB
C
273 lines
6.4 KiB
C
/*
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* RDC321x watchdog driver
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*
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* Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
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*
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* This driver is highly inspired from the cpu5_wdt driver
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/miscdevice.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/timer.h>
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#include <linux/completion.h>
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#include <linux/jiffies.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/mach-rdc/rdc321x_defs.h>
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#define RDC_WDT_MASK 0x80000000 /* Mask */
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#define RDC_WDT_EN 0x00800000 /* Enable bit */
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#define RDC_WDT_WTI 0x00200000 /* Generate a CPU reset/NMI/WDT irq when WDT timeout is reached */
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#define RDC_WDT_RST 0x00100000 /* Reset bit */
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#define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
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#define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
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#define RDC_WDT_CNT 0x00000001 /* WDT count */
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#define RDC_CLS_TMR 0x80003844 /* Clear timer */
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#define RDC_WDT_INTERVAL (HZ/10+1)
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int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static int ticks = 1000;
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/* some device data */
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static struct {
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struct completion stop;
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volatile int running;
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struct timer_list timer;
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volatile int queue;
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int default_ticks;
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unsigned long inuse;
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} rdc321x_wdt_device;
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/* generic helper functions */
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static void rdc321x_wdt_trigger(unsigned long unused)
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{
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if( rdc321x_wdt_device.running )
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ticks--;
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/* keep watchdog alive */
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outl(RDC_WDT_EN|inl(RDC3210_CFGREG_DATA), RDC3210_CFGREG_DATA);
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/* requeue?? */
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if (rdc321x_wdt_device.queue && ticks)
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mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
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else {
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/* ticks doesn't matter anyway */
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complete(&rdc321x_wdt_device.stop);
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}
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}
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static void rdc321x_wdt_reset(void)
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{
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ticks = rdc321x_wdt_device.default_ticks;
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}
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static void rdc321x_wdt_start(void)
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{
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if (!rdc321x_wdt_device.queue) {
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rdc321x_wdt_device.queue = 1;
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/* Clear the timer */
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outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR);
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/* Enable watchdog and set the timeout to 81.92 us */
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outl(RDC_WDT_EN|RDC_WDT_CNT, RDC3210_CFGREG_DATA);
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mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
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}
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/* if process dies, counter is not decremented */
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rdc321x_wdt_device.running++;
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}
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static int rdc321x_wdt_stop(void)
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{
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if (rdc321x_wdt_device.running)
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rdc321x_wdt_device.running = 0;
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ticks = rdc321x_wdt_device.default_ticks;
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return -EIO;
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}
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/* filesystem operations */
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static int rdc321x_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
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return -EBUSY;
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return nonseekable_open(inode, file);
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}
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static int rdc321x_wdt_release(struct inode *inode, struct file *file)
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{
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clear_bit(0, &rdc321x_wdt_device.inuse);
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return 0;
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}
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static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
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{
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void __user *argp = (void __user *)arg;
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unsigned int value;
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static struct watchdog_info ident =
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{
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.options = WDIOF_CARDRESET,
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.identity = "RDC321x WDT",
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};
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switch(cmd) {
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case WDIOC_KEEPALIVE:
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rdc321x_wdt_reset();
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break;
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case WDIOC_GETSTATUS:
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/* Read the value from the DATA register */
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value = inl(RDC3210_CFGREG_DATA);
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if ( copy_to_user(argp, &value, sizeof(int)) )
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return -EFAULT;
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break;
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case WDIOC_GETSUPPORT:
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if ( copy_to_user(argp, &ident, sizeof(ident)) )
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return -EFAULT;
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break;
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case WDIOC_SETOPTIONS:
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if ( copy_from_user(&value, argp, sizeof(int)) )
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return -EFAULT;
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switch(value) {
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case WDIOS_ENABLECARD:
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rdc321x_wdt_start();
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break;
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case WDIOS_DISABLECARD:
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return rdc321x_wdt_stop();
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default:
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return -EINVAL;
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}
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break;
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default:
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return -ENOTTY;
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}
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return 0;
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}
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static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
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{
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if ( !count )
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return -EIO;
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rdc321x_wdt_reset();
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return count;
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}
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static const struct file_operations rdc321x_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.ioctl = rdc321x_wdt_ioctl,
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.open = rdc321x_wdt_open,
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.write = rdc321x_wdt_write,
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.release = rdc321x_wdt_release,
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};
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static struct miscdevice rdc321x_wdt_misc = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &rdc321x_wdt_fops,
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};
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static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
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{
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int err;
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if ( (err = misc_register(&rdc321x_wdt_misc)) < 0 ) {
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printk(KERN_ERR PFX "misc_register failed\n");
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return err;
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}
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/* Reset the watchdog */
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outl(RDC_WDT_RST, RDC3210_CFGREG_DATA);
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init_completion(&rdc321x_wdt_device.stop);
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rdc321x_wdt_device.queue = 0;
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clear_bit(0, &rdc321x_wdt_device.inuse);
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setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
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rdc321x_wdt_device.default_ticks = ticks;
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printk(KERN_INFO PFX "init success\n");
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return 0;
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}
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static int rdc321x_wdt_remove(struct platform_device *pdev)
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{
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if (rdc321x_wdt_device.queue) {
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rdc321x_wdt_device.queue = 0;
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wait_for_completion(&rdc321x_wdt_device.stop);
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}
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misc_deregister(&rdc321x_wdt_misc);
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return 0;
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}
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static struct platform_driver rdc321x_wdt_driver = {
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.probe = rdc321x_wdt_probe,
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.remove = rdc321x_wdt_remove,
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.driver = {
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.owner = THIS_MODULE,
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.name = "rdc321x-wdt",
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},
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};
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static int __init rdc321x_wdt_init(void)
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{
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return platform_driver_register(&rdc321x_wdt_driver);
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}
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static void __exit rdc321x_wdt_exit(void)
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{
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platform_driver_unregister(&rdc321x_wdt_driver);
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}
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module_init(rdc321x_wdt_init);
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module_exit(rdc321x_wdt_exit);
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("RDC321x watchdog driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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