Gabor Juhos
16 years ago
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5ff6932c66
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3994f8e4c3
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/*
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* Driver for the Atheros AR71xx SoC's built-in hardware watchdog timer. |
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* |
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* Copyright (C) 2008 Gabor Juhos <juhosg@openwrt.org> |
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* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org> |
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* |
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* This driver was based on: drivers/watchdog/ixp4xx_wdt.c |
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* Author: Deepak Saxena <dsaxena@plexity.net> |
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* Copyright 2004 (c) MontaVista, Software, Inc. |
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* |
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* which again was based on sa1100 driver, |
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* Copyright (C) 2000 Oleg Drokin <green@crimea.edu> |
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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 version 2 as published |
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* by the Free Software Foundation. |
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* |
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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/platform_device.h> |
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#include <linux/types.h> |
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#include <linux/watchdog.h> |
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#include <asm/mach-ar71xx/ar71xx.h> |
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#define DRV_NAME "ar71xx-wdt" |
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#define DRV_DESC "Atheros AR71xx hardware watchdog driver" |
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#define DRV_VERSION "0.1.0" |
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#define WDT_TIMEOUT 15 /* seconds */ |
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static int nowayout = WATCHDOG_NOWAYOUT; |
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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, "Watchdog cannot be stopped once started " |
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"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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#endif |
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static unsigned long wdt_flags; |
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#define WDT_FLAGS_BUSY 0 |
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#define WDT_FLAGS_EXPECT_CLOSE 1 |
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static int wdt_timeout = WDT_TIMEOUT; |
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static int boot_status; |
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static int max_timeout; |
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static void inline ar71xx_wdt_keepalive(void) |
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{ |
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ar71xx_reset_wr(RESET_REG_WDOG, ar71xx_ahb_freq * wdt_timeout); |
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} |
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static void inline ar71xx_wdt_enable(void) |
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{ |
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printk(KERN_DEBUG DRV_NAME ": enabling watchdog timer\n"); |
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ar71xx_wdt_keepalive(); |
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ar71xx_reset_wr(RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_FCR); |
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} |
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static void inline ar71xx_wdt_disable(void) |
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{ |
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printk(KERN_DEBUG DRV_NAME ": disabling watchdog timer\n"); |
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ar71xx_reset_wr(RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_NONE); |
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} |
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static int ar71xx_wdt_set_timeout(int val) |
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{ |
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if (val < 1 || val > max_timeout) |
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return -EINVAL; |
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wdt_timeout = val; |
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ar71xx_wdt_keepalive(); |
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printk(KERN_DEBUG DRV_NAME ": timeout=%d secs\n", wdt_timeout); |
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return 0; |
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} |
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static int ar71xx_wdt_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(WDT_FLAGS_BUSY, &wdt_flags)) |
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return -EBUSY; |
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clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags); |
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ar71xx_wdt_enable(); |
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return nonseekable_open(inode, file); |
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} |
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static int ar71xx_wdt_release(struct inode *inode, struct file *file) |
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{ |
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if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags)) { |
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ar71xx_wdt_disable(); |
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} else { |
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printk(KERN_CRIT DRV_NAME ": device closed unexpectedly, " |
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"watchdog timer will not stop!\n"); |
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} |
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clear_bit(WDT_FLAGS_BUSY, &wdt_flags); |
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clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags); |
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return 0; |
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} |
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static ssize_t ar71xx_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_FLAGS_EXPECT_CLOSE, &wdt_flags); |
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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_FLAGS_EXPECT_CLOSE, |
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&wdt_flags); |
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} |
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} |
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ar71xx_wdt_keepalive(); |
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} |
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return len; |
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} |
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static struct watchdog_info ar71xx_wdt_info = { |
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
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WDIOF_MAGICCLOSE | WDIOF_CARDRESET, |
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.firmware_version = 0, |
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.identity = "AR71XX watchdog", |
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}; |
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static int ar71xx_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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int t; |
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int ret; |
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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, |
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&ar71xx_wdt_info, |
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sizeof(&ar71xx_wdt_info)) ? -EFAULT : 0; |
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break; |
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case WDIOC_GETSTATUS: |
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ret = put_user(0, (int *)arg) ? -EFAULT : 0; |
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break; |
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case WDIOC_GETBOOTSTATUS: |
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ret = put_user(boot_status, (int *)arg) ? -EFAULT : 0; |
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break; |
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case WDIOC_KEEPALIVE: |
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ar71xx_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(t, (int *)arg) ? -EFAULT : 0; |
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if (ret) |
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break; |
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ret = ar71xx_wdt_set_timeout(t); |
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if (ret) |
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break; |
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/* fallthrough */ |
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case WDIOC_GETTIMEOUT: |
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ret = put_user(wdt_timeout, (int *)arg) ? -EFAULT : 0; |
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break; |
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default: |
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ret = -ENOTTY; |
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break; |
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} |
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return ret; |
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} |
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static const struct file_operations ar71xx_wdt_fops = { |
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.owner = THIS_MODULE, |
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.write = ar71xx_wdt_write, |
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.ioctl = ar71xx_wdt_ioctl, |
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.open = ar71xx_wdt_open, |
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.release = ar71xx_wdt_release, |
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}; |
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static struct miscdevice ar71xx_wdt_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &ar71xx_wdt_fops, |
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}; |
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static int __devinit ar71xx_wdt_probe(struct platform_device *pdev) |
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{ |
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int ret; |
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max_timeout = (0xfffffffful / ar71xx_ahb_freq); |
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wdt_timeout = (max_timeout < WDT_TIMEOUT) ? max_timeout : WDT_TIMEOUT; |
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boot_status = |
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(ar71xx_reset_rr(RESET_REG_WDOG_CTRL) & WDOG_CTRL_LAST_RESET) ? |
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WDIOF_CARDRESET : 0; |
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ret = misc_register(&ar71xx_wdt_miscdev); |
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if (ret) |
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goto err_out; |
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printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n"); |
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printk(KERN_DEBUG DRV_NAME ": timeout=%d secs (max=%d)\n", |
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wdt_timeout, max_timeout); |
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return 0; |
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err_out: |
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return ret; |
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} |
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static int __devexit ar71xx_wdt_remove(struct platform_device *pdev) |
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{ |
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misc_deregister(&ar71xx_wdt_miscdev); |
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return 0; |
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} |
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static struct platform_driver ar71xx_wdt_driver = { |
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.probe = ar71xx_wdt_probe, |
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.remove = __devexit_p(ar71xx_wdt_remove), |
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.driver = { |
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.name = DRV_NAME, |
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.owner = THIS_MODULE, |
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}, |
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}; |
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static int __init ar71xx_wdt_init(void) |
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{ |
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return platform_driver_register(&ar71xx_wdt_driver); |
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} |
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module_init(ar71xx_wdt_init); |
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static void __exit ar71xx_wdt_exit(void) |
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{ |
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platform_driver_unregister(&ar71xx_wdt_driver); |
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} |
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module_exit(ar71xx_wdt_exit); |
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MODULE_DESCRIPTION(DRV_DESC); |
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MODULE_VERSION(DRV_VERSION); |
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MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org"); |
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MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:" DRV_NAME); |
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
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