This add watchdog driver for broadcom 47xx device. It uses the ssb subsytem to access embeded watchdog device. Because the watchdog timeout is very short (about 2s), a soft timer is used to increase the watchdog period. Note : A patch for exporting the ssb_watchdog_timer_set will be submitted on next linux-mips merge. Without this patch it can't be build as a module. Signed-off-by: Aleksandar Radovanovic <biblbroks@sezampro.rs> Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr> Tested-by: Florian Fainelli <florian@openwrt.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>tirimbino
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/*
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* Watchdog driver for Broadcom BCM47XX |
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* |
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* Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs> |
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* Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr> |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License |
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* as published by the Free Software Foundation; either version |
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* 2 of the License, or (at your option) any later version. |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/errno.h> |
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#include <linux/fs.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/miscdevice.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/reboot.h> |
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#include <linux/types.h> |
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#include <linux/uaccess.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/ssb/ssb_embedded.h> |
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#include <asm/mach-bcm47xx/bcm47xx.h> |
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#define DRV_NAME "bcm47xx_wdt" |
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#define WDT_DEFAULT_TIME 30 /* seconds */ |
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#define WDT_MAX_TIME 255 /* seconds */ |
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static int wdt_time = WDT_DEFAULT_TIME; |
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static int nowayout = WATCHDOG_NOWAYOUT; |
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module_param(wdt_time, int, 0); |
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MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default=" |
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__MODULE_STRING(WDT_DEFAULT_TIME) ")"); |
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#ifdef CONFIG_WATCHDOG_NOWAYOUT |
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module_param(nowayout, int, 0); |
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MODULE_PARM_DESC(nowayout, |
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"Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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#endif |
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static unsigned long bcm47xx_wdt_busy; |
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static char expect_release; |
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static struct timer_list wdt_timer; |
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static atomic_t ticks; |
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static inline void bcm47xx_wdt_hw_start(void) |
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{ |
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/* this is 2,5s on 100Mhz clock and 2s on 133 Mhz */ |
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ssb_watchdog_timer_set(&ssb_bcm47xx, 0xfffffff); |
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} |
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static inline int bcm47xx_wdt_hw_stop(void) |
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{ |
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return ssb_watchdog_timer_set(&ssb_bcm47xx, 0); |
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} |
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static void bcm47xx_timer_tick(unsigned long unused) |
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{ |
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if (!atomic_dec_and_test(&ticks)) { |
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bcm47xx_wdt_hw_start(); |
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mod_timer(&wdt_timer, jiffies + HZ); |
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} else { |
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printk(KERN_CRIT DRV_NAME "Watchdog will fire soon!!!\n"); |
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} |
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} |
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static inline void bcm47xx_wdt_pet(void) |
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{ |
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atomic_set(&ticks, wdt_time); |
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} |
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static void bcm47xx_wdt_start(void) |
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{ |
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bcm47xx_wdt_pet(); |
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bcm47xx_timer_tick(0); |
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} |
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static void bcm47xx_wdt_pause(void) |
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{ |
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del_timer_sync(&wdt_timer); |
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bcm47xx_wdt_hw_stop(); |
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} |
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static void bcm47xx_wdt_stop(void) |
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{ |
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bcm47xx_wdt_pause(); |
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} |
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static int bcm47xx_wdt_settimeout(int new_time) |
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{ |
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if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) |
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return -EINVAL; |
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wdt_time = new_time; |
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return 0; |
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} |
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static int bcm47xx_wdt_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(0, &bcm47xx_wdt_busy)) |
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return -EBUSY; |
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bcm47xx_wdt_start(); |
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return nonseekable_open(inode, file); |
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} |
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static int bcm47xx_wdt_release(struct inode *inode, struct file *file) |
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{ |
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if (expect_release == 42) { |
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bcm47xx_wdt_stop(); |
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} else { |
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printk(KERN_CRIT DRV_NAME |
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": Unexpected close, not stopping watchdog!\n"); |
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bcm47xx_wdt_start(); |
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} |
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clear_bit(0, &bcm47xx_wdt_busy); |
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expect_release = 0; |
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return 0; |
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} |
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static ssize_t bcm47xx_wdt_write(struct file *file, const char __user *data, |
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size_t len, loff_t *ppos) |
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{ |
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if (len) { |
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if (!nowayout) { |
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size_t i; |
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expect_release = 0; |
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for (i = 0; i != len; i++) { |
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char c; |
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if (get_user(c, data + i)) |
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return -EFAULT; |
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if (c == 'V') |
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expect_release = 42; |
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} |
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} |
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bcm47xx_wdt_pet(); |
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} |
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return len; |
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} |
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static struct watchdog_info bcm47xx_wdt_info = { |
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.identity = DRV_NAME, |
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.options = WDIOF_SETTIMEOUT | |
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WDIOF_KEEPALIVEPING | |
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WDIOF_MAGICCLOSE, |
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}; |
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static long bcm47xx_wdt_ioctl(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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int __user *p = argp; |
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int new_value, retval = -EINVAL;; |
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switch (cmd) { |
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case WDIOC_GETSUPPORT: |
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return copy_to_user(argp, &bcm47xx_wdt_info, |
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sizeof(bcm47xx_wdt_info)) ? -EFAULT : 0; |
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case WDIOC_GETSTATUS: |
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case WDIOC_GETBOOTSTATUS: |
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return put_user(0, p); |
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case WDIOC_SETOPTIONS: |
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if (get_user(new_value, p)) |
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return -EFAULT; |
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if (new_value & WDIOS_DISABLECARD) { |
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bcm47xx_wdt_stop(); |
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retval = 0; |
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} |
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if (new_value & WDIOS_ENABLECARD) { |
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bcm47xx_wdt_start(); |
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retval = 0; |
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} |
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return retval; |
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case WDIOC_KEEPALIVE: |
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bcm47xx_wdt_pet(); |
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return 0; |
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case WDIOC_SETTIMEOUT: |
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if (get_user(new_value, p)) |
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return -EFAULT; |
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if (bcm47xx_wdt_settimeout(new_value)) |
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return -EINVAL; |
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bcm47xx_wdt_pet(); |
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case WDIOC_GETTIMEOUT: |
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return put_user(wdt_time, p); |
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default: |
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return -ENOTTY; |
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} |
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} |
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static int bcm47xx_wdt_notify_sys(struct notifier_block *this, |
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unsigned long code, void *unused) |
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{ |
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if (code == SYS_DOWN || code == SYS_HALT) |
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bcm47xx_wdt_stop(); |
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return NOTIFY_DONE; |
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} |
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static const struct file_operations bcm47xx_wdt_fops = { |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.unlocked_ioctl = bcm47xx_wdt_ioctl, |
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.open = bcm47xx_wdt_open, |
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.release = bcm47xx_wdt_release, |
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.write = bcm47xx_wdt_write, |
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}; |
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static struct miscdevice bcm47xx_wdt_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &bcm47xx_wdt_fops, |
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}; |
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static struct notifier_block bcm47xx_wdt_notifier = { |
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.notifier_call = bcm47xx_wdt_notify_sys, |
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}; |
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static int __init bcm47xx_wdt_init(void) |
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{ |
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int ret; |
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if (bcm47xx_wdt_hw_stop() < 0) |
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return -ENODEV; |
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setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L); |
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if (bcm47xx_wdt_settimeout(wdt_time)) { |
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bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME); |
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printk(KERN_INFO DRV_NAME ": " |
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"wdt_time value must be 0 < wdt_time < %d, using %d\n", |
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(WDT_MAX_TIME + 1), wdt_time); |
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} |
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ret = register_reboot_notifier(&bcm47xx_wdt_notifier); |
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if (ret) |
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return ret; |
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ret = misc_register(&bcm47xx_wdt_miscdev); |
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if (ret) { |
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unregister_reboot_notifier(&bcm47xx_wdt_notifier); |
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return ret; |
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} |
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printk(KERN_INFO "BCM47xx Watchdog Timer enabled (%d seconds%s)\n", |
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wdt_time, nowayout ? ", nowayout" : ""); |
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return 0; |
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} |
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static void __exit bcm47xx_wdt_exit(void) |
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{ |
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if (!nowayout) |
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bcm47xx_wdt_stop(); |
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misc_deregister(&bcm47xx_wdt_miscdev); |
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unregister_reboot_notifier(&bcm47xx_wdt_notifier); |
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} |
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module_init(bcm47xx_wdt_init); |
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module_exit(bcm47xx_wdt_exit); |
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MODULE_AUTHOR("Aleksandar Radovanovic"); |
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MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); |
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MODULE_LICENSE("GPL"); |
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
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