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![Olaf Hering](/assets/img/avatar_default.png)
While looking for possible candidates for our udev.rules package, I found a few odd ->name properties. /dev/watchdog has minor 130 according to devices.txt. Since all watchdog drivers use the misc_register() call, they will end up in /sys/class/misc/$foo. udev may create the /dev/watchdog node if the driver is loaded. I dont have such a device, so I cant test it. The drivers below provide names with spaces and even with / in it. Not a big deal, but apps may expect /dev/watchdog. Signed-off-by: Olaf Hering <olh@suse.de> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
220 lines
4.6 KiB
C
220 lines
4.6 KiB
C
/*
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* drivers/watchdog/ixp2000_wdt.c
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*
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* Watchdog driver for Intel IXP2000 network processors
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*
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* Adapted from the IXP4xx watchdog driver by Lennert Buytenhek.
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* The original version 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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#include <linux/config.h>
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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 <asm/hardware.h>
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#include <asm/uaccess.h>
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static int nowayout = WATCHDOG_NOWAYOUT;
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static unsigned int heartbeat = 60; /* (secs) Default is 1 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 unsigned long wdt_tick_rate;
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static void
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wdt_enable(void)
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{
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ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE);
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ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE);
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ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
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ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE);
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}
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static void
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wdt_disable(void)
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{
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ixp2000_reg_write(IXP2000_T4_CTL, 0);
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}
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static void
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wdt_keepalive(void)
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{
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ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
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}
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static int
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ixp2000_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 nonseekable_open(inode, file);
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}
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static ssize_t
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ixp2000_wdt_write(struct file *file, const char *data, 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 struct watchdog_info ident = {
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.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING,
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.identity = "IXP2000 Watchdog",
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};
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static int
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ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOIOCTLCMD;
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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_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 > 60) {
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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_keepalive();
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/* Fall through */
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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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case WDIOC_KEEPALIVE:
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wdt_enable();
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ret = 0;
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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
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ixp2000_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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printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
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"timer will not stop\n");
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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 struct file_operations ixp2000_wdt_fops =
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{
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = ixp2000_wdt_write,
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.ioctl = ixp2000_wdt_ioctl,
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.open = ixp2000_wdt_open,
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.release = ixp2000_wdt_release,
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};
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static struct miscdevice ixp2000_wdt_miscdev =
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{
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &ixp2000_wdt_fops,
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};
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static int __init ixp2000_wdt_init(void)
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{
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if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) {
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printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n");
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return -EIO;
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}
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wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256;
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return misc_register(&ixp2000_wdt_miscdev);
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}
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static void __exit ixp2000_wdt_exit(void)
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{
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misc_deregister(&ixp2000_wdt_miscdev);
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}
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module_init(ixp2000_wdt_init);
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module_exit(ixp2000_wdt_exit);
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MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net">);
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MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog");
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
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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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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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