b6b4d9b8d0
Clean up the advantech watchdog code and inspect for BKL problems Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
352 lines
8.0 KiB
C
352 lines
8.0 KiB
C
/*
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* Advantech Single Board Computer WDT driver
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*
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* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
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*
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* Based on acquirewdt.c which is based on wdt.c.
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* Original copyright messages:
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*
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* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
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* http://www.redhat.com
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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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* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
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* warranty for any of this software. This material is provided
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* "AS-IS" and at no charge.
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*
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* (c) Copyright 1995 Alan Cox <alan@redhat.com>
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*
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* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
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* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
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*
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* 16-Oct-2002 Rob Radez <rob@osinvestor.com>
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* Clean up ioctls, clean up init + exit, add expect close support,
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* add wdt_start and wdt_stop as parameters.
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*/
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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/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/fs.h>
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#include <linux/ioport.h>
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#include <linux/platform_device.h>
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#include <linux/init.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#define DRV_NAME "advantechwdt"
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#define PFX DRV_NAME ": "
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#define WATCHDOG_NAME "Advantech WDT"
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#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
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static struct platform_device *advwdt_platform_device; /* the watchdog platform device */
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static unsigned long advwdt_is_open;
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static char adv_expect_close;
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/*
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* You must set these - there is no sane way to probe for this board.
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*
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* To enable or restart, write the timeout value in seconds (1 to 63)
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* to I/O port wdt_start. To disable, read I/O port wdt_stop.
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* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
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* check your manual (at least the PCA-6159 seems to be different -
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* the manual says wdt_stop is 0x43, not 0x443).
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* (0x43 is also a write-only control register for the 8254 timer!)
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*/
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static int wdt_stop = 0x443;
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module_param(wdt_stop, int, 0);
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MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
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static int wdt_start = 0x443;
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module_param(wdt_start, int, 0);
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MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
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static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in seconds. 1<= timeout <=63, default="
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__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
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static int nowayout = 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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/*
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* Watchdog Operations
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*/
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static void advwdt_ping(void)
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{
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/* Write a watchdog value */
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outb_p(timeout, wdt_start);
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}
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static void advwdt_disable(void)
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{
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inb_p(wdt_stop);
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}
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static int advwdt_set_heartbeat(int t)
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{
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if (t < 1 || t > 63)
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return -EINVAL;
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timeout = t;
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return 0;
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}
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/*
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* /dev/watchdog handling
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*/
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static ssize_t advwdt_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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if (count) {
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if (!nowayout) {
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size_t i;
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adv_expect_close = 0;
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for (i = 0; i != count; i++) {
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char c;
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if (get_user(c, buf+i))
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return -EFAULT;
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if (c == 'V')
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adv_expect_close = 42;
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}
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}
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advwdt_ping();
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}
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return count;
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}
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static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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int new_timeout;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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static struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
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.firmware_version = 1,
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.identity = WATCHDOG_NAME,
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};
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switch (cmd) {
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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_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_KEEPALIVE:
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advwdt_ping();
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break;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, p))
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return -EFAULT;
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if (advwdt_set_heartbeat(new_timeout))
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return -EINVAL;
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advwdt_ping();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(timeout, p);
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case WDIOC_SETOPTIONS:
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{
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int options, retval = -EINVAL;
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if (get_user(options, p))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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advwdt_disable();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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advwdt_ping();
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retval = 0;
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}
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return retval;
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}
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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 advwdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &advwdt_is_open))
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return -EBUSY;
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/*
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* Activate
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*/
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advwdt_ping();
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return nonseekable_open(inode, file);
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}
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static int
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advwdt_close(struct inode *inode, struct file *file)
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{
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if (adv_expect_close == 42) {
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advwdt_disable();
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} else {
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printk(KERN_CRIT PFX
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"Unexpected close, not stopping watchdog!\n");
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advwdt_ping();
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}
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clear_bit(0, &advwdt_is_open);
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adv_expect_close = 0;
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return 0;
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}
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/*
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* Kernel Interfaces
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*/
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static const struct file_operations advwdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = advwdt_write,
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.unlocked_ioctl = advwdt_ioctl,
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.open = advwdt_open,
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.release = advwdt_close,
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};
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static struct miscdevice advwdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &advwdt_fops,
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};
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/*
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* Init & exit routines
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*/
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static int __devinit advwdt_probe(struct platform_device *dev)
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{
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int ret;
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if (wdt_stop != wdt_start) {
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if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
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printk(KERN_ERR PFX
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"I/O address 0x%04x already in use\n",
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wdt_stop);
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ret = -EIO;
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goto out;
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}
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}
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if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
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printk(KERN_ERR PFX
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"I/O address 0x%04x already in use\n",
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wdt_start);
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ret = -EIO;
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goto unreg_stop;
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}
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/* Check that the heartbeat value is within it's range ; if not reset to the default */
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if (advwdt_set_heartbeat(timeout)) {
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advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
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printk(KERN_INFO PFX
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"timeout value must be 1<=x<=63, using %d\n", timeout);
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}
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ret = misc_register(&advwdt_miscdev);
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if (ret != 0) {
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printk(KERN_ERR PFX
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"cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, ret);
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goto unreg_regions;
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}
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printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
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timeout, nowayout);
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out:
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return ret;
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unreg_regions:
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release_region(wdt_start, 1);
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unreg_stop:
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if (wdt_stop != wdt_start)
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release_region(wdt_stop, 1);
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goto out;
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}
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static int __devexit advwdt_remove(struct platform_device *dev)
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{
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misc_deregister(&advwdt_miscdev);
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release_region(wdt_start,1);
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if(wdt_stop != wdt_start)
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release_region(wdt_stop,1);
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return 0;
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}
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static void advwdt_shutdown(struct platform_device *dev)
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{
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/* Turn the WDT off if we have a soft shutdown */
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advwdt_disable();
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}
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static struct platform_driver advwdt_driver = {
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.probe = advwdt_probe,
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.remove = __devexit_p(advwdt_remove),
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.shutdown = advwdt_shutdown,
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.driver = {
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.owner = THIS_MODULE,
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.name = DRV_NAME,
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},
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};
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static int __init advwdt_init(void)
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{
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int err;
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printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
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err = platform_driver_register(&advwdt_driver);
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if (err)
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return err;
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advwdt_platform_device = platform_device_register_simple(DRV_NAME,
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-1, NULL, 0);
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if (IS_ERR(advwdt_platform_device)) {
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err = PTR_ERR(advwdt_platform_device);
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goto unreg_platform_driver;
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}
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return 0;
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unreg_platform_driver:
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platform_driver_unregister(&advwdt_driver);
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return err;
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}
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static void __exit advwdt_exit(void)
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{
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platform_device_unregister(advwdt_platform_device);
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platform_driver_unregister(&advwdt_driver);
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printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
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}
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module_init(advwdt_init);
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module_exit(advwdt_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
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MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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