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![Gustavo A. R. Silva](/assets/img/avatar_default.png)
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200707171121.GA13472@embeddedor Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
227 lines
5.1 KiB
C
227 lines
5.1 KiB
C
/*
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* drivers/watchdog/m54xx_wdt.c
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*
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* Watchdog driver for ColdFire MCF547x & MCF548x processors
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* Copyright 2010 (c) Philippe De Muyter <phdm@macqel.be>
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*
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* Adapted from the IXP4xx watchdog driver, which carries these notices:
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*
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* Author: Deepak Saxena <dsaxena@plexity.net>
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*
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* Copyright 2004 (c) MontaVista, Software, Inc.
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* Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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/kernel.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/bitops.h>
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#include <linux/ioport.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <asm/coldfire.h>
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#include <asm/m54xxsim.h>
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#include <asm/m54xxgpt.h>
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static bool nowayout = WATCHDOG_NOWAYOUT;
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static unsigned int heartbeat = 30; /* (secs) Default is 0.5 minute */
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static unsigned long wdt_status;
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#define WDT_IN_USE 0
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#define WDT_OK_TO_CLOSE 1
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static void wdt_enable(void)
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{
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unsigned int gms0;
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/* preserve GPIO usage, if any */
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gms0 = __raw_readl(MCF_GPT_GMS0);
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if (gms0 & MCF_GPT_GMS_TMS_GPIO)
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gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK
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| MCF_GPT_GMS_OD);
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else
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gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD;
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__raw_writel(gms0, MCF_GPT_GMS0);
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__raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) |
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MCF_GPT_GCIR_CNT(0xffff), MCF_GPT_GCIR0);
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gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE;
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__raw_writel(gms0, MCF_GPT_GMS0);
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}
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static void wdt_disable(void)
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{
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unsigned int gms0;
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/* disable watchdog */
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gms0 = __raw_readl(MCF_GPT_GMS0);
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gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE);
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__raw_writel(gms0, MCF_GPT_GMS0);
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}
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static void wdt_keepalive(void)
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{
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unsigned int gms0;
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gms0 = __raw_readl(MCF_GPT_GMS0);
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gms0 |= MCF_GPT_GMS_OCPW(0xA5);
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__raw_writel(gms0, MCF_GPT_GMS0);
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}
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static int m54xx_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(WDT_IN_USE, &wdt_status))
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return -EBUSY;
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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wdt_enable();
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return stream_open(inode, file);
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}
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static ssize_t m54xx_wdt_write(struct file *file, const char *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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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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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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set_bit(WDT_OK_TO_CLOSE, &wdt_status);
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}
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}
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wdt_keepalive();
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}
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return len;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING,
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.identity = "Coldfire M54xx Watchdog",
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};
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static long m54xx_wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user((struct watchdog_info *)arg, &ident,
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sizeof(ident)) ? -EFAULT : 0;
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break;
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case WDIOC_GETSTATUS:
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ret = put_user(0, (int *)arg);
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break;
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(0, (int *)arg);
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break;
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case WDIOC_KEEPALIVE:
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wdt_keepalive();
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ret = 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, (int *)arg);
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if (ret)
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break;
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if (time <= 0 || time > 30) {
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ret = -EINVAL;
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break;
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}
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heartbeat = time;
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wdt_enable();
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fallthrough;
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case WDIOC_GETTIMEOUT:
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ret = put_user(heartbeat, (int *)arg);
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break;
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}
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return ret;
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}
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static int m54xx_wdt_release(struct inode *inode, struct file *file)
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{
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if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
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wdt_disable();
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else {
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pr_crit("Device closed unexpectedly - timer will not stop\n");
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wdt_keepalive();
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}
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clear_bit(WDT_IN_USE, &wdt_status);
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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return 0;
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}
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static const struct file_operations m54xx_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = m54xx_wdt_write,
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.unlocked_ioctl = m54xx_wdt_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = m54xx_wdt_open,
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.release = m54xx_wdt_release,
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};
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static struct miscdevice m54xx_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &m54xx_wdt_fops,
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};
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static int __init m54xx_wdt_init(void)
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{
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if (!request_mem_region(MCF_GPT_GCIR0, 4, "Coldfire M54xx Watchdog")) {
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pr_warn("I/O region busy\n");
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return -EBUSY;
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}
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pr_info("driver is loaded\n");
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return misc_register(&m54xx_wdt_miscdev);
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}
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static void __exit m54xx_wdt_exit(void)
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{
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misc_deregister(&m54xx_wdt_miscdev);
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release_mem_region(MCF_GPT_GCIR0, 4);
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}
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module_init(m54xx_wdt_init);
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module_exit(m54xx_wdt_exit);
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MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
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MODULE_DESCRIPTION("Coldfire M54xx Watchdog");
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)");
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
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MODULE_LICENSE("GPL");
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