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247 lines
6.0 KiB
C
247 lines
6.0 KiB
C
/*
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* Watchdog driver for the BCM963xx devices
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*
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* Copyright (C) 2007 OpenWrt.org
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* Florian Fainelli <florian@openwrt.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/module.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/notifier.h>
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#include <linux/watchdog.h>
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#include <linux/timer.h>
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#include <linux/jiffies.h>
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#include <linux/completion.h>
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#include <linux/ioport.h>
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typedef struct bcm963xx_timer {
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unsigned short unused0;
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unsigned char timer_mask;
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#define TIMER0EN 0x01
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#define TIMER1EN 0x02
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#define TIMER2EN 0x04
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unsigned char timer_ints;
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#define TIMER0 0x01
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#define TIMER1 0x02
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#define TIMER2 0x04
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#define WATCHDOG 0x08
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unsigned long timer_ctl0;
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unsigned long timer_ctl1;
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unsigned long timer_ctl2;
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#define TIMERENABLE 0x80000000
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#define RSTCNTCLR 0x40000000
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unsigned long timer_cnt0;
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unsigned long timer_cnt1;
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unsigned long timer_cnt2;
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unsigned long wdt_def_count;
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/* Write 0xff00 0x00ff to Start timer
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* Write 0xee00 0x00ee to Stop and re-load default count
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* Read from this register returns current watch dog count
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*/
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unsigned long wdt_ctl;
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/* Number of 40-MHz ticks for WD Reset pulse to last */
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unsigned long wdt_rst_count;
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} bcm963xx_timer;
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static struct bcm963xx_wdt_device {
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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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} bcm963xx_wdt_device;
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static int ticks = 1000;
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#define WDT_BASE 0xfffe0200
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#define WDT ((volatile bcm963xx_timer * const) WDT_BASE)
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#define BCM963XX_INTERVAL (HZ/10+1)
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static void bcm963xx_wdt_trigger(unsigned long unused)
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{
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if (bcm963xx_wdt_device.running)
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ticks--;
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/* Load the default ticking value into the reset counter register */
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WDT->wdt_rst_count = bcm963xx_wdt_device.default_ticks;
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if (bcm963xx_wdt_device.queue && ticks) {
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bcm963xx_wdt_device.timer.expires = jiffies + BCM963XX_INTERVAL;
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add_timer(&bcm963xx_wdt_device.timer);
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}
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else {
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complete(&bcm963xx_wdt_device.stop);
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}
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}
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static void bcm963xx_wdt_reset(void)
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{
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ticks = bcm963xx_wdt_device.default_ticks;
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/* Also reload default count */
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WDT->wdt_def_count = ticks;
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WDT->wdt_ctl = 0xee00;
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WDT->wdt_ctl = 0x00ee;
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}
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static void bcm963xx_wdt_start(void)
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{
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if (!bcm963xx_wdt_device.queue) {
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bcm963xx_wdt_device.queue;
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/* Enable the watchdog by writing 0xff00 ,then 0x00ff to the control register */
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WDT->wdt_ctl = 0xff00;
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WDT->wdt_ctl = 0x00ff;
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bcm963xx_wdt_device.timer.expires = jiffies + BCM963XX_INTERVAL;
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add_timer(&bcm963xx_wdt_device.timer);
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}
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bcm963xx_wdt_device.running++;
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}
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static int bcm963xx_wdt_stop(void)
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{
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if (bcm963xx_wdt_device.running)
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bcm963xx_wdt_device.running = 0;
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ticks = bcm963xx_wdt_device.default_ticks;
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/* Stop the watchdog by writing 0xee00 then 0x00ee to the control register */
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WDT->wdt_ctl = 0xee00;
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WDT->wdt_ctl = 0x00ee;
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return -EIO;
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}
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static int bcm963xx_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &bcm963xx_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 bcm963xx_wdt_release(struct inode *inode, struct file *file)
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{
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clear_bit(0, &bcm963xx_wdt_device.inuse);
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return 0;
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}
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static int bcm963xx_wdt_ioctl(struct inode *inode, struct file *file,
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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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.options = WDIOF_CARDRESET,
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.identity = "BCM963xx WDT",
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};
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switch (cmd) {
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case WDIOC_KEEPALIVE:
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bcm963xx_wdt_reset();
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break;
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case WDIOC_GETSTATUS:
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/* Reading from the control register will return the current value */
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value = WDT->wdt_ctl;
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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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bcm963xx_wdt_start();
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break;
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case WDIOS_DISABLECARD:
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bcm963xx_wdt_stop();
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break;
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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 int bcm963xx_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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bcm963xx_wdt_reset();
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return count;
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}
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static const struct file_operations bcm963xx_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = bcm963xx_wdt_write,
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.ioctl = bcm963xx_wdt_ioctl,
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.open = bcm963xx_wdt_open,
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.release = bcm963xx_wdt_release,
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};
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static struct miscdevice bcm963xx_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &bcm963xx_wdt_fops,
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};
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static void __exit bcm963xx_wdt_exit(void)
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{
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if (bcm963xx_wdt_device.queue ){
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bcm963xx_wdt_device.queue = 0;
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wait_for_completion(&bcm963xx_wdt_device.stop);
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}
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misc_deregister(&bcm963xx_wdt_miscdev);
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}
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static int __init bcm963xx_wdt_init(void)
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{
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int ret = 0;
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printk("Broadcom BCM963xx Watchdog timer\n");
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ret = misc_register(&bcm963xx_wdt_miscdev);
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if (ret) {
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printk(KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret);
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return ret;
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}
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init_completion(&bcm963xx_wdt_device.stop);
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bcm963xx_wdt_device.queue = 0;
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clear_bit(0, &bcm963xx_wdt_device.inuse);
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init_timer(&bcm963xx_wdt_device.timer);
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bcm963xx_wdt_device.timer.function = bcm963xx_wdt_trigger;
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bcm963xx_wdt_device.timer.data = 0;
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bcm963xx_wdt_device.default_ticks = ticks;
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return ret;
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}
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module_init(bcm963xx_wdt_init);
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module_exit(bcm963xx_wdt_exit);
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("Broadcom BCM963xx Watchdog driver");
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MODULE_LICENSE("GPL");
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