Subversion Repositories or1k

/*

 *      Advantech Single Board Computer WDT driver for Linux 2.4.x

 *

 *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>

 *

 *      Based on acquirewdt.c which is based on wdt.c.

 *      Original copyright messages:

 *

 *      (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.

 *                              http://www.redhat.com

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 *

 *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide

 *      warranty for any of this software. This material is provided

 *      "AS-IS" and at no charge.

 *

 *      (c) Copyright 1995    Alan Cox <alan@redhat.com>

 *

 *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>

 *          Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT

 */

#include <linux/config.h>

#include <linux/module.h>

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/ioport.h>

#include <linux/fcntl.h>

#include <asm/io.h>

#include <asm/uaccess.h>

#include <asm/system.h>

#include <linux/notifier.h>

#include <linux/reboot.h>

#include <linux/init.h>

static unsigned long advwdt_is_open;

static char adv_expect_close;

/*

 *      You must set these - there is no sane way to probe for this board.

 *

 *      To enable or restart, write the timeout value in seconds (1 to 63)

 *      to I/O port wdt_start.  To disable, read I/O port wdt_stop.

 *      Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but

 *      check your manual (at least the PCA-6159 seems to be different -

 *      the manual says wdt_stop is 0x43, not 0x443).

 *      (0x43 is also a write-only control register for the 8254 timer!)

 */

static int wdt_stop = 0x443;

static int wdt_start = 0x443;

static int wd_margin = 60; /* 60 sec default timeout */

#ifdef CONFIG_WATCHDOG_NOWAYOUT

static int nowayout = 1;

#else

static int nowayout = 0;

#endif

MODULE_PARM(nowayout,"i");

MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

/*

 *      Kernel methods.

 */

#ifndef MODULE

static int __init adv_setup(char *str)

{

        int ints[4];

        str = get_options(str, ARRAY_SIZE(ints), ints);

        if(ints[0] > 0){

                wdt_stop = ints[1];

                if(ints[0] > 1)

                        wdt_start = ints[2];

        }

        return 1;

}

__setup("advwdt=", adv_setup);

#endif /* !MODULE */

MODULE_PARM(wdt_stop, "i");

MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");

MODULE_PARM(wdt_start, "i");

MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");

static void

advwdt_ping(void)

{

        /* Write a watchdog value */

        outb_p(wd_margin, wdt_start);

}

static void

advwdt_disable(void)

{

        inb_p(wdt_stop);

}

static ssize_t

advwdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)

{

        /*  Can't seek (pwrite) on this device  */

        if (ppos != &file->f_pos)

                return -ESPIPE;

        if (count) {

                if (!nowayout) {

                        size_t i;

                        adv_expect_close = 0;

                        for (i = 0; i != count; i++) {

                                char c;

                                if(get_user(c, buf+i))

                                        return -EFAULT;

                                if (c == 'V')

                                        adv_expect_close = 42;

                        }

                }

                        advwdt_ping();

        }

        return count;

}

static int

advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,

          unsigned long arg)

{

        int new_margin;

        static struct watchdog_info ident = {

                options:                WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,

                firmware_version:       0,

                identity:               "Advantech WDT"

        };

        switch (cmd) {

        case WDIOC_GETSUPPORT:

          if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))

            return -EFAULT;

          break;

        case WDIOC_GETSTATUS:

        case WDIOC_GETBOOTSTATUS:

          return put_user(0, (int *)arg);

        case WDIOC_KEEPALIVE:

          advwdt_ping();

          break;

        case WDIOC_SETTIMEOUT:

          if (get_user(new_margin, (int *)arg))

                  return -EFAULT;

          if ((new_margin < 1) || (new_margin > 63))

                  return -EINVAL;

          wd_margin = new_margin;

          advwdt_ping();

          /* Fall */

        case WDIOC_GETTIMEOUT:

          return put_user(wd_margin, (int *)arg);

        case WDIOC_SETOPTIONS:

        {

          int options, retval = -EINVAL;

          if (get_user(options, (int *)arg))

            return -EFAULT;

          if (options & WDIOS_DISABLECARD) {

            advwdt_disable();

            retval = 0;

          }

          if (options & WDIOS_ENABLECARD) {

            advwdt_ping();

            retval = 0;

          }

          return retval;

        }

        default:

          return -ENOTTY;

        }

        return 0;

}

static int

advwdt_open(struct inode *inode, struct file *file)

{

        if (test_and_set_bit(0, &advwdt_is_open))

                return -EBUSY;

        /*

         *      Activate

         */

        advwdt_ping();

        return 0;

}

static int

advwdt_close(struct inode *inode, struct file *file)

{

        if (adv_expect_close == 42) {

                advwdt_disable();

        } else {

                printk(KERN_CRIT "advancetechwdt: Unexpected close, not stopping watchdog!\n");

                advwdt_ping();

        }

        clear_bit(0, &advwdt_is_open);

        adv_expect_close = 0;

        return 0;

}

/*

 *      Notifier for system down

 */

static int

advwdt_notify_sys(struct notifier_block *this, unsigned long code,

        void *unused)

{

        if (code == SYS_DOWN || code == SYS_HALT) {

                /* Turn the WDT off */

                advwdt_disable();

        }

        return NOTIFY_DONE;

}

/*

 *      Kernel Interfaces

 */

static struct file_operations advwdt_fops = {

        owner:          THIS_MODULE,

        llseek:         no_llseek,

        write:          advwdt_write,

        ioctl:          advwdt_ioctl,

        open:           advwdt_open,

        release:        advwdt_close,

};

static struct miscdevice advwdt_miscdev = {

        minor:          WATCHDOG_MINOR,

        name:           "watchdog",

        fops:           &advwdt_fops,

};

/*

 *      The WDT needs to learn about soft shutdowns in order to

 *      turn the timebomb registers off.

 */

static struct notifier_block advwdt_notifier = {

        advwdt_notify_sys,

        NULL,

};

static int __init

advwdt_init(void)

{

        printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");

        misc_register(&advwdt_miscdev);

        if(wdt_stop != wdt_start)

                request_region(wdt_stop, 1, "Advantech WDT");

        request_region(wdt_start, 1, "Advantech WDT");

        register_reboot_notifier(&advwdt_notifier);

        return 0;

}

static void __exit

advwdt_exit(void)

{

        misc_deregister(&advwdt_miscdev);

        unregister_reboot_notifier(&advwdt_notifier);

        if(wdt_stop != wdt_start)

                release_region(wdt_stop,1);

        release_region(wdt_start,1);

}

module_init(advwdt_init);

module_exit(advwdt_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");

MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");

EXPORT_NO_SYMBOLS;

/* end of advantechwdt.c */