Subversion Repositories test_project

/*

 *      Watchdog driver for the SA11x0/PXA2xx

 *

 *      (c) Copyright 2000 Oleg Drokin <green@crimea.edu>

 *          Based on SoftDog driver by Alan Cox <alan@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 Oleg Drokin nor iXcelerator.com admit liability nor provide

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

 *      "AS-IS" and at no charge.

 *

 *      (c) Copyright 2000           Oleg Drokin <green@crimea.edu>

 *

 *      27/11/2000 Initial release

 */

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/init.h>

#include <linux/bitops.h>

#ifdef CONFIG_ARCH_PXA

#include <asm/arch/pxa-regs.h>

#endif

#include <asm/hardware.h>

#include <asm/uaccess.h>

#define OSCR_FREQ               CLOCK_TICK_RATE

static unsigned long sa1100wdt_users;

static int pre_margin;

static int boot_status;

/*

 *      Allow only one person to hold it open

 */

static int sa1100dog_open(struct inode *inode, struct file *file)

{

        if (test_and_set_bit(1,&sa1100wdt_users))

                return -EBUSY;

        /* Activate SA1100 Watchdog timer */

        OSMR3 = OSCR + pre_margin;

        OSSR = OSSR_M3;

        OWER = OWER_WME;

        OIER |= OIER_E3;

        return nonseekable_open(inode, file);

}

/*

 * The watchdog cannot be disabled.

 *

 * Previous comments suggested that turning off the interrupt by

 * clearing OIER[E3] would prevent the watchdog timing out but this

 * does not appear to be true (at least on the PXA255).

 */

static int sa1100dog_release(struct inode *inode, struct file *file)

{

        printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");

        clear_bit(1, &sa1100wdt_users);

        return 0;

}

static ssize_t sa1100dog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)

{

        if (len)

                /* Refresh OSMR3 timer. */

                OSMR3 = OSCR + pre_margin;

        return len;

}

static struct watchdog_info ident = {

        .options        = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,

        .identity       = "SA1100/PXA255 Watchdog",

};

static int sa1100dog_ioctl(struct inode *inode, struct file *file,

        unsigned int cmd, unsigned long arg)

{

        int ret = -ENOTTY;

        int time;

        void __user *argp = (void __user *)arg;

        int __user *p = argp;

        switch (cmd) {

        case WDIOC_GETSUPPORT:

                ret = copy_to_user(argp, &ident,

                                   sizeof(ident)) ? -EFAULT : 0;

                break;

        case WDIOC_GETSTATUS:

                ret = put_user(0, p);

                break;

        case WDIOC_GETBOOTSTATUS:

                ret = put_user(boot_status, p);

                break;

        case WDIOC_SETTIMEOUT:

                ret = get_user(time, p);

                if (ret)

                        break;

                if (time <= 0 || time > 255) {

                        ret = -EINVAL;

                        break;

                }

                pre_margin = OSCR_FREQ * time;

                OSMR3 = OSCR + pre_margin;

                /*fall through*/

        case WDIOC_GETTIMEOUT:

                ret = put_user(pre_margin / OSCR_FREQ, p);

                break;

        case WDIOC_KEEPALIVE:

                OSMR3 = OSCR + pre_margin;

                ret = 0;

                break;

        }

        return ret;

}

static const struct file_operations sa1100dog_fops =

{

        .owner          = THIS_MODULE,

        .llseek         = no_llseek,

        .write          = sa1100dog_write,

        .ioctl          = sa1100dog_ioctl,

        .open           = sa1100dog_open,

        .release        = sa1100dog_release,

};

static struct miscdevice sa1100dog_miscdev =

{

        .minor          = WATCHDOG_MINOR,

        .name           = "watchdog",

        .fops           = &sa1100dog_fops,

};

static int margin __initdata = 60;              /* (secs) Default is 1 minute */

static int __init sa1100dog_init(void)

{

        int ret;

        /*

         * Read the reset status, and save it for later.  If

         * we suspend, RCSR will be cleared, and the watchdog

         * reset reason will be lost.

         */

        boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0;

        pre_margin = OSCR_FREQ * margin;

        ret = misc_register(&sa1100dog_miscdev);

        if (ret == 0)

                printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",

                       margin);

        return ret;

}

static void __exit sa1100dog_exit(void)

{

        misc_deregister(&sa1100dog_miscdev);

}

module_init(sa1100dog_init);

module_exit(sa1100dog_exit);

MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");

MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");

module_param(margin, int, 0);

MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");

MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);